AP Bio MIDTERM (Chapters 50-56, 1-13)
energy is not.
Answer: A
fluorescent probes may introduce background artifacts.
Answer: A
56 card image Which molecule shown above contains a carboxyl group? A) A B) B C) C D) D E) E
Answer: D
2
Answer: E
47 A beaker contains 100 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the results of this mixing? A) The concentration of Na⁺ ion rises. B) The concentration of Cl⁻ ion will be 0.1 M. C) The concentration of undissociated H₂O molecules remains unchanged. D) The pH of the beaker's contents will be neutral. E) The pH of the beaker's contents falls.
Answer: E
32 Which of the following contains hydrolytic enzymes? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome
Answer: A
42 42) Why do populations grow more slowly as they approach their carrying capacity? A) Density-dependent factors lead to fewer births and increased mortality. B) Density-independent factors lead to fewer births and increased mortality. C) Hormonal changes promote higher death rates in crowded populations. D) Individuals voluntarily stop mating so that overcrowding does not occur. E) The incoming energy decreases in populations experiencing a high rate of increase.
Answer: A
55 Photorespiration lowers the efficiency of photosynthesis by A) carbon dioxide molecules. B) 3-phosphoglycerate molecules. C) ATP molecules. D) ribulose bisphosphate molecules. E) RuBP carboxylase molecules.
Answer: B
61 61) Action potentials in the heart move from one contractile cell to the next via A) chemical synapses using acetylcholine. B) chemical synapses using norepinephrine. C) electrical synapses using gap junctions. D) myelinated motor neurons. E) non-myelinated motor neurons.
Answer: C
N-selected
Answer: D
31 31) If an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can
must have which of the following? A) at most, 2 alleles for that gene B) up to 18 chromosomes with that gene C) up to 18 genes for that trait D) a haploid number of 9 chromosomes E) up to, but not more than, 18 different traits/ Answer: A
Who was
were the first to propose that cell membranes are phospholipid bilayers? A) H. Davson and J. Danielli B) I. Langmuir C) C. Overton D) S. Singer and G. Nicolson E) E. Gorter and F. Grendel/ Answer: E
34 What results from an unequal sharing of electrons between atoms? A) a nonpolar covalent bond B) a polar covalent bond C) an ionic bond D) a hydrogen bond E) a hydrophobic interaction
Answer: B
34 Which of the following statements regarding enzymes is true? A) Enzymes increase the rate of a reaction by making the reaction more exergonic. B) Enzymes increase the rate of a reaction by lowering the activation energy barrier. C) Enzymes increase the rate of a reaction by reducing the rate of reverse reactions. D) Enzymes change the equilibrium point of the reactions they catalyze. E) Enzymes make the rate of a reaction independent of substrate concentrations.
Answer: B
35 35) Lateral inhibition via amacrine cells in the mammalian retina A) underlies habituation of vision. B) enhances visual contrast. C) prevents bleaching in bright light. D) is required for color vision to occur. E) recycles neurotransmitter molecules.
Answer: B
52 card image The lettered circle in Figure 12.1 shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is gray. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages. 52) What is the correct chromosomal condition at the prometaphase of mitosis? A) A B) B C) C D) D E) E
Answer: B
53 A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in A) peroxisomes. B) lysosomes. C) Golgi vesicles. D) vacuoles. E) secretory vesicles.
Answer: B
7 When oxygen is released as a result of photosynthesis, it is a direct by-product of A) reducing NADP⁺. B) splitting water molecules. C) chemiosmosis. D) the electron transfer system of photosystem I. E) the electron transfer system of photosystem II.
Answer: B
1) Which of the following ecological locations has the greatest species diversity? A) tundra B) deciduous forests C) tropics D) grasslands E) islands
Answer: C
42 Which type of organelle is found in plant cells but not in animal cells? A) ribosomes B) mitochondria C) nuclei D) plastids E) none of these
Answer: D
69 card image If HIV first enters the cell in an endocytotic vesicle, instead of directly fusing with the plasma membrane, then A) HIV infection should be hindered by microtubule polymerization inhibitors such as nocodazole. B) HIV infection should be more efficient at lower temperatures. C) intact cortical actin microfilaments should interfere with HIV infection. D) cells lacking integrins should be resistant to HIV infection. E) addition of ligands for other cell-surface receptors to stimulate their endocytosis should increase the efficiency of HIV infection.
Answer: A
7 7) Which of the following is an example of Müllerian mimicry? A) two species of unpalatable butterfly that have the same color pattern B) a day-flying hawkmoth that looks like a wasp C) a chameleon that changes its color to look like a dead leaf D) two species of rattlesnakes that both rattle their tails E) two species of moths with wing spots that look like owl's eyes
Answer: A
101 Which class of biological polymer has the greatest functional variety? A) polysaccharides B) proteins C) DNA D) RNA
Answer: B
12 A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? A) Eukarya B) Archaea C) Animalia D) Protista E) Fungi
Answer: B
83 card image Which step in Figure 9.1 is a redox reaction? A) A B) B C) C D) D E) E
Answer: C
30 30) A guinea pig loves the lettuce kept in the refrigerator and squeals each time the refrigerator door opens. What term best applies to this behavior? A) sign stimulus B) cognition C) imprinting D) classical conditioning E) operant conditioning
Answer: D
54 Which theme(s) is
are illustrated when a biology class is comparing the rates of photosynthesis between leaves of a flowering plant species (Gerbera jamesonii) and a species of fern (Polypodium polypodioides)? A) I only B) II only C) I and III D) I and VII E) I, III, and V/ Answer: E
53 Which theme(s) is
are illustrated when a group of students is trying to establish which phase of cell division in root tips happens most quickly? A) IV only B) V only C) VII only D) IV, V, and VI E) V, VI, and VII/ Answer: D
enter this +
- value into the nitrogen budget of the ecosystem. D) Do nothing. The Canada geese visitation to the lake would have negligible impact on the nitrogen budget of the pond. E) Put a net over the pond so that no more migrating flocks can land on the pond and alter the nitrogen balance of the pond./ Answer: C
1) The centromere is a region in which A) chromatids remain attached to one another until anaphase. B) metaphase chromosomes become aligned at the metaphase plate. C) chromosomes are grouped during telophase. D) the nucleus is located prior to mitosis. E) new spindle microtubules form at either end.
Answer: A
10 10) Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect A) the formation of the mitotic spindle. B) anaphase. C) formation of the centrioles. D) chromatid assembly. E) the S phase of the cell cycle.
Answer: A
27 27) Review the formula for effective population size. Imagine a population of 1,000 small rodents. Of these, 300 are breeding females, 300 are breeding males, and 400 are nonbreeding juveniles. What is the effective population size? A) 1,000 B) 1,200 C) 600 D) 400 E) 300
Answer: C
12 Which of the following is the smallest closed system? A) a cell B) an organism C) an ecosystem D) Earth E) the universe
Answer: E
55 card image Which component is cholesterol? A) A B) B C) C D) D E) E
Answer: E
52 Which theme(s) is
are best illustrated by a group of investigators who are trying to classify and explain the ecology of an area known as the Big Thicket? A) I only B) II only C) VIII only D) IV and VI E) I and II/ Answer: E
yellow = hot. C) stage of development
maturity. D) their receptiveness to mate. E) the success of the mating behavior of each of the throat color phenotypes./ Answer: E
16 16) What is the biological significance of genetic diversity between populations? A) Genes for adaptive traits to local conditions make microevolution possible. B) The population that is most fit would survive by competitive exclusion. C) Genetic diversity allows for species stability by preventing speciation. D) Isolated populations become more fit. E) Diseases and parasites are not spread between separated populations.
Answer: A
19 Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH 8 solution. What would be likely to happen? A) The isolated chloroplasts will make ATP. B) The Calvin cycle will be activated. C) Cyclic photophosphorylation will occur. D) The isolated chloroplasts will generate oxygen gas. E) The isolated chloroplasts will reduce NADP⁺ to NADPH.
Answer: A
26 26) According to bottom-up and top-down control models of community organization, which of the following expressions would imply that an increase in the size of a carnivore (C) population would negatively impact on its prey (P) population, but not vice versa? A) P ← C B) P → C C) C ↔ P D) P ← C → P E) C ← P →
Answer: A
3 3) An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one woodlot and 20 per square mile in another woodlot. What was the ecologist comparing? A) density B) dispersion C) carrying capacity D) cohorts E) range
Answer: A
3 3) If there are 20 chromatids in a cell, how many centromeres are there? A) 10 B) 20 C) 30 D) 40 E) 80
Answer: A
30 30) In temperate lakes, the surface water is replenished with nutrients during turnovers that occur in the A) autumn and spring. B) autumn and winter. C) spring and summer. D) summer and winter. E) summer and autumn.
Answer: A
14 An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function? A) transporting ions against an electrochemical gradient B) cell-cell recognition C) maintaining fluidity of the phospholipid bilayer D) attaching to the cytoskeleton E) establishing the diffusion barrier to charged molecules
Answer: B
15 An atom has 6 electrons in its outer shell. How many unpaired electrons does it have? A) 0 B) 2 C) 4 D) 6 E) 2 or 4
Answer: B
16 Which of the following is true for all exergonic reactions? A) The products have more total energy than the reactants. B) The reaction proceeds with a net release of free energy. C) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. D) A net input of energy from the surroundings is required for the reactions to proceed. E) The reactions are rapid.
Answer: B
2 The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction A) gains electrons and gains potential energy. B) loses electrons and loses potential energy. C) gains electrons and loses potential energy. D) loses electrons and gains potential energy. E) neither gains nor loses electrons, but gains or loses potential energy.
Answer: B
2 The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called? A) a covalent bond B) a hydrogen bond C) an ionic bond D) a hydrophilic bond E) a van der Waals interaction
Answer: B
62 card image What wavelength of light in the figure is most effective in driving photosynthesis? A) 420 mm B) 475 mm C) 575 mm D) 625 mm E) 730 mm
Answer: A
48 The smallest cell structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope is A) a mitochondrion. B) a microtubule. C) a ribosome. D) a microfilament. E) a nuclear pore.
Answer: A
6 6) A cow's herbivorous diet indicates that it is a(n) A) primary consumer. B) secondary consumer. C) decomposer. D) autotroph. E) producer.
Answer: A
67 67) A region of the canary forebrain shrinks during the nonbreeding season and enlarges when breeding season begins. This change is probably associated with the annual A) addition of new syllables to a canary's song repertoire. B) crystallization of subsong into adult songs. C) sensitive period in which canary parents imprint on new offspring. D) renewal of mating and nest-building behaviors. E) elimination of the memorized template for songs sung the previous year.
Answer: A
72 72) Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species? A) tropical rain forest B) savanna C) desert D) temperate broadleaf forest E) temperate grassland
Answer: A
79 79) Which of the following statements about human population in industrialized countries is incorrect? A) Life history is r-selected. B) Average family size is relatively small. C) The population has undergone the demographic transition. D) The survivorship curve is Type I. E) Age distribution is relatively uniform.
Answer: A
79 Which statement is true of all atoms that are anions? A) The atom has more electrons than protons. B) The atom has more protons than electrons. C) The atom has fewer protons than does a neutral atom of the same element. D) The atom has more neutrons than protons. E) The net charge is 1-.
Answer: A
9 Which of the following types of reactions would decrease the entropy within a cell? A) anabolic reactions B) hydrolysis C) respiration D) digestion E) catabolic reactions
Answer: A
10 10) Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes. Which of the following best describes the interactions between dwarf mistletoes and trees? A) mutualism B) parasitism C) commensalism D) facilitation E) competition
Answer: B
105 Which of the following statements concerning unsaturated fats is true? A) They are more common in animals than in plants. B) They have double bonds in the carbon chains of their fatty acids. C) They generally solidify at room temperature. D) They contain more hydrogen than do saturated fats having the same number of carbon atoms. E) They have fewer fatty acid molecules per fat molecule.
Answer: B
24 The transport of pyruvate into mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion? A) active transport B) diffusion C) facilitated diffusion D) through a channel E) through a pore
Answer: A
25 25) Aquatic primary productivity is most limited by which of the following? A) light and nutrient availability B) predation by primary consumers C) increased pressure with depth D) pollution E) temperature
Answer: A
25 25) When does the synaptonemal complex disappear? A) late prophase of meiosis I B) during fertilization or fusion of gametes C) early anaphase of meiosis I D) mid-prophase of meiosis II E) late metaphase of meiosis II
Answer: A
27 Testosterone and estradiol are A) soluble in water. B) structural isomers of each other. C) proteins. D) lipids. E) enantiomers of each other.
Answer: B
3 3) Sensory-transducing cells that fire both graded potentials and action potentials are found in A) vision. B) gustation. C) olfaction. D) audition.
Answer: C
3 3) Which of the following best describes resource partitioning? A) competitive exclusion that results in the success of the superior species B) slight variations in niche that allow similar species to coexist C) two species that can coevolve to share identical niches D) differential resource utilization that results in a decrease in community species diversity E) a climax community that is reached when no new niches are available
Answer: B
39 A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following? A) lower cytoplasmic levels of cAMP B) an increase in receptor tyrosine kinase activity C) a decrease in transcriptional activity of certain genes D) an increase in cytosolic calcium concentration E) a decrease in G protein activity
Answer: C
76 Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle? A) pyruvate B) malate or fumarate C) acetyl CoA D) α-ketoglutarate E) succinyl CoA
Answer: C
8 Which branch of biology is concerned with the naming and classifying of organisms? A) informatics B) schematic biology C) taxonomy D) genomics E) evolution
Answer: C
80 80) Which sensory distinction is not encoded by a difference in neuron identity? A) white and red B) red and green C) loud and faint D) salty and sweet E) spicy and cool
Answer: C
20 20) The greatest cause of the biodiversity crisis, the one which includes all of the others, is A) pollution. B) global warming. C) habitat destruction. D) introduced species. E) human overpopulation.
Answer: E
50 Where do apoptotic signals come from? A) the nucleus only B) the ER only C) ligand binding only D) mitochondrial protein leakage only E) all of the above
Answer: E
87 card image Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate would supply the carbon skeleton for synthesis of a five-carbon amino acid (see Figure 9.2)? A) succinate B) malate C) citrate D) α-ketoglutarate E) isocitrate
Answer: D
94 [SEE IMAGE FOR CARD #84] Which of the following molecules could be joined together by a phosphodiester type of covalent bond? A) 3 and 4 B) 3 and 8 C) 6 and 15 D) 11 and 12 E) 11 and 13
Answer: D
58 card image Which curve(s) on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher? A) curves 1 and 5 B) curves 2 and 4 C) curves 2 and 5 D) curves 3 and 4 E) curves 3 and 5
Answer: E
2 2) Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? A) 4 B) 8 C) 16 D) 32 E) 64
Answer: D
55 card image Use the following diagram of five islands formed at around the same time near a particular mainland, as well as MacArthur and Wilson's island biogeography principles, to answer the following question. Figure 54.4 55) Which island would likely have the greatest species diversity? A) A B) B C) C D) D E) E
Answer: A
56 Cells require which of the following to form cilia or flagella? A) centrosomes B) laminin C) actin D) intermediate filaments E) secretory vesicles
Answer: A
79 79) During the contraction of a vertebrate skeletal muscle fiber, calcium ions A) break cross-bridges by acting as a cofactor in the hydrolysis of ATP. B) bind with troponin, changing its shape so that the myosin-binding sites on actin are exposed. C) transmit action potentials from the motor neuron to the muscle fiber. D) spread action potentials through the T tubules. E) re-establish the polarization of the plasma membrane following an action potential.
Answer: B
rainfall is consistently high in Labrador. D) Labrador is too windy to support tall plants, such as palm trees. E) Labrador receives sunlight of lower duration and intensity than does Land's End.
Answer: B
1) How do the Taylor Glacier bacteria produce their energy? A) photosynthesis B) heterotrophism C) chemoautotrophism D) thermophobism E) chemosynthesis
Answer: C
62 62) The hydrostatic skeleton of the earthworm allows it to move around in its environment by A) walking on its limbs. B) crawling with its feet. C) swimming with its setae. D) using peristaltic contractions of its circular and longitudinal muscles. E) alternating contractions and relaxations of its flagellae.
Answer: D
77 77) Nitrifying bacteria participate in the nitrogen cycle mainly by A) converting nitrogen gas to ammonia. B) releasing ammonium from organic compounds, thus returning it to the soil. C) converting ammonia to nitrogen gas, which returns to the atmosphere. D) converting ammonium to nitrate, which plants absorb. E) incorporating nitrogen into amino acids and organic compounds.
Answer: D
13 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? A) domain Bacteria, kingdom Prokaryota B) domain Archaea, kingdom Bacteria C) domain Eukarya, kingdom Plantae D) domain Eukarya, kingdom Protista E) domain Eukarya, kingdom Fungi
Answer: E
16 16) Which of the following environmental features might influence microclimates? A) forest canopy B) freshly plowed field C) log on the forest floor D) large boulder E) All of the options are correct.
Answer: E
30 An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum? A) tyrosine kinases B) serine
threonine kinases C) phosphodiesterase D) phospholipase C E) adenylyl cyclase/ Answer: D
12 12) In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis? A) seedless plants B) dinoflagellates C) diatoms D) dinoflagellates and diatoms only E) seedless plants, dinoflagellates, and diatoms
Answer: D
12 Which statement describes the functioning of photosystem II? A) Light energy excites electrons in the thylakoid membrane electron transport chain. B) Photons are passed along to a reaction-center chlorophyll. C) The P680 chlorophyll donates a pair of protons to NADP⁺, which is thus converted to NADPH. D) The electron vacancies in P680⁺ are filled by electrons derived from water. E) The splitting of water yields molecular carbon dioxide as a by-product.
Answer: D
13 13) An earthworm without a statocyst would not be able to A) move. B) sense light. C) hear. D) orient with respect to gravity. E) respond to touch.
Answer: D
13 13) Movement of the chromosomes during anaphase would be most affected by a drug that A) reduces cyclin concentrations. B) increases cyclin concentrations. C) prevents elongation of microtubules. D) prevents shortening of microtubules. E) prevents attachment of the microtubules to the kinetochore.
Answer: D
13 The precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the standard atomic mass, or even from sample to sample. Why? A) The element may undergo radioactive decay. B) The element may react with itself and gain or lose subatomic particles. C) The atoms of the element form chemical bonds with each other, and that changes the weight of the element. D) The element may have multiple stable isotopes, and the isotopic composition may vary from sample to sample. E) The amount of energy absorbed by the element affects the mass of its electrons, and thus the atomic mass can vary slightly.
Answer: D
13 Which of the following is true of metabolism in its entirety in all organisms? A) Metabolism depends on a constant supply of energy from food. B) Metabolism depends on an organism's adequate hydration. C) Metabolism uses all of an organism's resources. D) Metabolism consists of all the energy transformation reactions in an organism. E) Metabolism manages the increase of entropy in an organism.
Answer: D
13 Which of the following is true of transcription factors? A) They regulate the synthesis of DNA in response to a signal. B) They transcribe ATP into cAMP. C) They initiate the epinephrine response in animal cells. D) They control gene expression. E) They regulate the synthesis of lipids in the cytoplasm.
Answer: D
13 Which of the following statements best describes the carbon atoms present in a seed-eating bird? A) Inorganic carbon atoms in the seeds were incorporated into organic molecules by the bird. B) The carbon atoms ultimately came from the soil. C) The carbon atoms are ultimately derived from coal. D) The carbon atoms ultimately came from carbon dioxide incorporated into sugars through photosynthesis. E) The carbon atoms ultimately came from simple organic compounds that formed abiotically from inorganic carbon, hydrogen, oxygen, and nitrogen atoms.
Answer: D
14 14) Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA? A) G₀ B) G₁ C) S D) G₂ E) M
Answer: D
14 14) The cellular membrane across which ion flow varies during auditory transduction is the A) tectorial membrane. B) tympanic membrane. C) round-window membrane. D) hair cell membrane. E) basilar membrane.
Answer: D
14 14) Which of the following is the most direct threat to biodiversity? A) increased levels of atmospheric carbon dioxide B) the depletion of the ozone layer C) overexploitation of selected species D) habitat destruction E) zoned reserves
Answer: D
14 One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this? A) G protein-coupled receptors B) ligand-gated ion channels C) steroid receptors D) receptor tyrosine kinases
Answer: D
14 Why are carbohydrates and fats considered high energy foods? A) They have a lot of oxygen atoms. B) They have no nitrogen in their makeup. C) They can have very long carbon skeletons. D) They have a lot of electrons associated with hydrogen. E) They are easily reduced.
Answer: D
14 Why does ice float in liquid water? A) The high surface tension of liquid water keeps the ice on top. B) The ionic bonds between the molecules in ice prevent the ice from sinking. C) Ice always has air bubbles that keep it afloat. D) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. E) The crystalline lattice of ice causes it to be denser than liquid water.
Answer: D
15 15) According to most conservation biologists, the single greatest threat to global biodiversity is A) chemical pollution of water and air. B) stratospheric ozone depletion. C) overexploitation of certain species. D) alteration or destruction of the physical habitat. E) global climate change resulting from a variety of human activities.
Answer: D
15 15) Which of the following best defines a cohort? A) a group of individuals that inhabits a small isolated region within the range for the species B) all of the individuals that are annually added to a population by birth and immigration C) the reproductive males and females within the population D) a group of the individuals from the same age group, from birth until they are all dead E) the number of individuals that annually die or emigrate out of a population
Answer: D
15 In the years since the proposal of the fluid mosaic model of the cell membrane, which of the following observations has been added to the model? A) The membrane is only fluid across a very narrow temperature range. B) Proteins rarely move, even though they possibly can do so. C) Unsaturated lipids are excluded from the membranes. D) The concentration of protein molecules is now known to be much higher. E) The proteins are known to be made of only acidic amino acids.
Answer: D
16
Answer: D
90 card image Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle (see Figure 9.2)? A) 1 ATP, 2 CO₂, 3 NADH, and 1 FADH₂ B) 2 ATP, 2 CO₂, 3 NADH, and 3 FADH₂ C) 3 ATP, 3 CO₂, 3 NADH, and 3 FADH₂ D) 3 ATP, 6 CO₂, 9 NADH, and 3 FADH₂ E) 38 ATP, 6 CO₂, 3 NADH, and 12 FADH₂
Answer: D
16 Charles Darwin proposed a mechanism for descent with modification that stated that organisms of a particular species are adapted to their environment when they possess A) non-inheritable traits that enhance their survival in the local environment. B) non-inheritable traits that enhance their reproductive success in the local environment. C) non-inheritable traits that enhance their survival and reproductive success in the local environment. D) inheritable traits that enhance their survival and reproductive success in the local environment. E) inheritable traits that decrease their survival and reproductive success in the local environment.
Answer: D
16 If radioactive deoxythymidine triphosphate (dTTP) is added to a culture of rapidly growing bacterial cells, where in the cell would you expect to find the greatest concentration of radioactivity? A) nucleus B) cytoplasm C) endoplasmic reticulum D) nucleoid E) ribosomes
Answer: D
17 17) Which of these ecosystems accounts for the largest amount of Earth's net primary productivity? A) tundra B) savanna C) salt marsh D) open ocean E) tropical rain forest
Answer: D
17 Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? A) the splitting of water B) the absorption of light energy by chlorophyll C) the flow of electrons from photosystem II to photosystem I D) the synthesis of ATP E) the reduction of NADP⁺
Answer: D
17 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? A) a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium B) a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings C) an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment D) a chemical reaction in which both the reactants and products are not being produced or used in any active metabolic pathway E) no possibility of having chemical equilibrium in any living cell
Answer: D
92 card image Figure 9.3 shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain? A) oxygen, carbon dioxide, and water B) NAD⁺, FAD, and electrons C) NADH, FADH₂, and protons D) NADH, FADH₂, and O₂ E) oxygen and protons
Answer: D
94 card image Which of the protein complexes labeled with Roman numerals in Figure 9.3 will transfer electrons to O₂? A) complex I B) complex II C) complex III D) complex IV E) All of the complexes can transfer electrons to O₂.
Answer: D
95 [SEE IMAGE FOR CARD #84] Which of the following molecules is the pentose sugar found in RNA? A) 1 B) 4 C) 6 D) 12 E) 13
Answer: D
96 In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO₂, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A. These three steps result in the formation of A) acetyl CoA, O₂, and ATP. B) acetyl CoA, FADH₂, and CO₂. C) acetyl CoA, FAD, H₂, and CO₂. D) acetyl CoA, NADH, H⁺, and CO₂. E) acetyl CoA, NAD⁺, ATP, and CO₂.
Answer: D
18 18) Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis? A) The chromosomes are "reeled in" by the contraction of spindle microtubules. B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. C) Nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles. D) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules. E) The chromosomes are "reeled in" by the contraction of spindle microtubules, motor proteins of the kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles.
Answer: D
18 18) Which of these ecosystems has the highest net primary productivity per square meter? A) savanna B) open ocean C) boreal forest D) tropical rain forest E) temperate forest
Answer: D
18 Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question. A. operant conditioning B. agonistic behavior C. innate behavior D. imprinting E. altruistic behavior 18) A mother goat can recognize its own kid by smell. A) A B) B C) C D) D E) E
Answer: D
18 The atomic number of neon is 10. Therefore, which of the following is most correct about an atom of neon? A) It has 8 electrons in its outer electron shell. B) It is inert. C) It has an atomic mass of 10 daltons. D) It has 8 electrons in its outer electron shell and it is inert. E) It has 8 electrons in its outer electron shell, it is inert, and it has an atomic mass of 10 daltons.
Answer: D
18 The receptors for a group of signaling molecules known as growth factors are often A) ligand-gated ion channels. B) G protein-coupled receptors. C) cyclic AMP. D) receptor tyrosine kinases. E) neurotransmitters.
Answer: D
19 19) How might the extinction of some Pacific Island bats called "flying foxes" threaten the survival of over 75% of the tree species in those islands? A) The bats eat the insects that harm competitor plants. B) The bats consume the fruit including the seeds that would disrupt the trees' reproductive cycle. C) The bats roost in the trees and fertilize soil around the trees with their nitrogen-rich droppings. D) The bats pollinate the trees and disperse seeds. E) The bats pierce the fruit, which allows the seeds to germinate.
Answer: D
19 19) Which data is most useful to measure primary productivity in a terrestrial ecosystem? A) temperature readings B) potential evapotranspiration C) intensity of solar radiation D) annual precipitation E) amount of carbon fixed
Answer: D
19 19) Which of the following can utilize both mitosis and meiosis in the correct circumstances? A) a haploid animal cell B) a diploid cell from a plant stem C) any diploid animal cell D) a plantlike protist E) an archaebacterium
Answer: D
19 19) Which of the following is a function of those spindle microtubules that do not attach to kinetochores? A) maintaining an appropriate spacing among the moving chromosomes B) producing a cleavage furrow when telophase is complete C) providing the ATP needed by the fibers attached to kinetochores D) maintaining the region of overlap of microtubules in the cell's center E) pulling the poles of the spindles closer to one another
Answer: D
19 Through time, the lineage that led to modern whales shows a change from four-limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by A) natural philosophy. B) creationism. C) the hierarchy of the biological organization of life. D) natural selection. E) feedback inhibition.
Answer: D
2 2) What is the estimated number of extant species on Earth? A) 1,000 to 50,000 B) 50,000 to 150,000 C) 500,000 to 1,000,000 D) 10,000,000 to 100,000,000 E) 5 billion to 10 billion
Answer: D
2 What is most likely to happen to an animal's target cells that lack receptors for local regulators? A) They might compensate by receiving nutrients via a factor. B) They could develop normally in response to neurotransmitters instead. C) They could divide but never reach full size. D) They might not be able to multiply in response to growth factors from nearby cells. E) Hormones would not be able to interact with target cells.
Answer: D
20 20) Starting from a single individual, what is the size of a population of bacteria that reproduce by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited resources and no mortality.) A) 6 B) 18 C) 128 D) 512 E) 1,024
Answer: D
20 20) Which of the following is a true statement regarding mineral nutrients in soils and their implication for primary productivity? A) Globally, phosphorous availability is most limiting to primary productivity. B) Adding a nonlimiting nutrient will stimulate primary productivity. C) Adding more of a limiting nutrient will increase primary productivity, indefinitely. D) Phosphorous is sometimes unavailable to producers due to leaching. E) Alkaline soils are more productive than acidic soils.
Answer: D
20 20) Which of the following terms is used by ecologists to describe the community interaction where one organism makes the environment more suitable for another organism? A) parasitism B) mutualism C) inhibition D) facilitation E) commensalism
Answer: D
20 In a plant cell, where are the ATP synthase complexes located? A) thylakoid membrane only B) plasma membrane only C) inner mitochondrial membrane only D) thylakoid membrane and inner mitochondrial membrane E) thylakoid membrane and plasma membrane
Answer: D
21 21) Mechanoreceptors that react to low frequency waves are part of the A) human sense of taste. B) pain receptors in birds. C) human sense of smell. D) lateral line systems in fish. E) eyes in arthropods.
Answer: D
22 22) Approximately how many kg of carnivore biomass can be supported by a field plot containing 1,000 kg of plant material? A) 10,000 B) 1,000 C) 100 D) 10 E) 1
Answer: D
22 22) In July 2008, the United States had a population of approximately 302,000,000 people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%? A) 2,700,000 B) 5,500,000 C) 303,000,000 D) 304,000,000 E) 2,710,800,000
Answer: D
22 22) The lateral line system in fish transduces sensory information in a manner that, among these choices, is most similar to A) human vision. B) human olfaction. C) human gustation. D) human vestibular sense. E) human thermoreception.
Answer: D
22 22) Which of the following is (are) required for motor proteins to function in the movement of chromosomes toward the poles of the mitotic spindle? A) intact centromeres B) an MTOC (microtubule organizing center) C) a kinetochore attached to the metaphase plate D) ATP as an energy source E) synthesis of cohesin
Answer: D
22 Two atoms appear to have the same mass number. These atoms A) must have the same atomic number. B) must have the same number of electrons. C) must have the same chemical properties. D) must have the same number of protons + neutrons. E) must have the same atomic number, the same number of protons + neutrons, the same number of electrons, and the same chemical properties.
Answer: D
22 Which of the following is a false statement concerning amino groups? A) They are basic in pH. B) They are found in amino acids. C) They contain nitrogen. D) They are nonpolar. E) They are components of urea.
Answer: D
22 Which of the following is true of the evolution of cell membranes? A) Cell membranes have stopped evolving now that they are fluid mosaics. B) Cell membranes cannot evolve if the membrane proteins do not. C) The evolution of cell membranes is driven by the evolution of glycoproteins and glycolipids. D) All components of membranes evolve in response to natural selection. E) An individual organism selects its preferred type of cell membrane for particular functions.
Answer: D
22 Why is Darwin considered original in his thinking? A) He provided examples of organisms that had evolved over time. B) He demonstrated that evolution is continuing to occur now. C) He described the relationship between genes and evolution. D) He proposed the mechanism that explained how evolution takes place. E) He observed that organisms produce large numbers of offspring.
Answer: D
23 23) After telophase I of meiosis, the chromosomal makeup of each daughter cell is A) diploid, and the chromosomes are each composed of a single chromatid. B) diploid, and the chromosomes are each composed of two chromatids. C) haploid, and the chromosomes are each composed of a single chromatid. D) haploid, and the chromosomes are each composed of two chromatids. E) tetraploid, and the chromosomes are each composed of two chromatids.
Answer: D
23 23) Which of the following examples poses the greatest potential threat to biodiversity? A) replanting, after a clear cut, a monoculture of Douglas fir trees on land that consisted of old-growth Douglas fir, western cedar, and western hemlock B) allowing previously used farmland to go fallow and begin to fill in with weeds and then shrubs and saplings C) trapping and relocating large predators, such as mountain lions, that pose a threat as they move into areas of relatively dense human populations D) importing an Asian insect into the United States to control a weed that competes with staple crops E) releasing sterilized rainbow trout to boost the sport fishing of a river system that contains native brook trout
Answer: D
23 Why are lipids and proteins free to move laterally in membranes? A) The interior of the membrane is filled with liquid water. B) Lipids and proteins repulse each other in the membrane. C) Hydrophilic portions of the lipids are in the interior of the membrane. D) There are only weak hydrophobic interactions in the interior of the membrane. E) Molecules such as cellulose can pull them in various directions.
Answer: D
24 24) Coral reefs can be found on the southern east coast of the United States but not at similar latitudes on the southern west coast. Differences in which of the following most likely account for this? A) sunlight intensity B) precipitation C) day length D) ocean currents E) salinity
Answer: D
24 24) How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis? A) They have twice the amount of cytoplasm and half the amount of DNA. B) They have half the number of chromosomes and half the amount of DNA. C) They have the same number of chromosomes and half the amount of DNA. D) They have half the number of chromosomes and one-fourth the amount of DNA. E) They have half the amount of cytoplasm and twice the amount of DNA.
Answer: D
24 24) Which of the following proteins are involved in binary fission as well as eukaryotic mitotic division? A) cyclins B) Cdks C) MPF D) actin and tubulin E) cohesins
Answer: D
99 Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated further, however, the ability to synthesize ATP is lost. After the further agitation of the membrane vesicles, what must be lost from the membrane? A) the ability of NADH to transfer electrons to the first acceptor in the electron transport chain B) the prosthetic groups like heme from the transport system C) cytochromes D) ATP synthase, in whole or in part E) the contact required between inner and outer membrane surfaces
Answer: D
In yeast signal transduction, the yeast cells A) must physically and directly interact. B) produce signal molecules that change themselves so they can interact with one another. C) produce response molecules that diffuse to other yeast cells. D) secrete molecules that result in response by other yeast cells. E) mate, after which the new cells secrete hybrid signals.
Answer: D
Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A) 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' B) 5'-AGCT-3' with 5'-TCGA-3' C) 5'-GCGC-3' with 5'-TATA-3' D) 5'-ATGC-3' with 5'-GCAT-3' E) All of these pairs are correct.
Answer: D
it is primed to do cellular work. E) has less energy than before its phosphorylation and therefore less energy for cellular work.
Answer: D
it is the next "frontier" for feeding humanity. B) Because it is so immense, the pelagic ocean biome is globally uniform. C) Globally, more photosynthesis occurs in the ocean neritic biome than in the pelagic biome. D) Pelagic ocean photosynthetic activity is disproportionately low in relation to the size of the biome. E) The most abundant animals are vertebrate fishes.
Answer: D
more primitive cells have smaller sizes D) the need for a surface area of sufficient area to support the cell's metabolic needs E) rigid cell walls that limit cell size expansion
Answer: D
nature will attain its own balance. D) Limit the burning of fossil fuels and regulate our loss of forested areas. E) Recycle as much as possible.
Answer: D
25 25) Sensillae are A) smell receptors in animals with hydrostatic skeletons. B) mechanoreceptors that help birds remain oriented during flight. C) a specific type of hair cell in the human ear. D) insect taste receptors found on feet and mouthparts. E) olfactory hairs located on insect antennae.
Answer: D
25 25) Using which of the following techniques would enable your lab group to distinguish between a cell in G₂ and a cell from the same organism in G₁? A) fluorescence microscopy B) electron microscopy C) spectrophotometry D) radioactive-labeled nucleotides E) labeled kinetochore proteins
Answer: D
25 25) Which of the following conditions is the most likely indicator of a population in an extinction vortex? A) The population is geographically divided into smaller populations. B) The species in question is found only in small pockets of its former range. C) The effective population size of the species falls below 500. D) Genetic measurements indicate a loss of genetic variation over time. E) The population is no longer connected by corridors.
Answer: D
25 A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it A) would function only as an acid because of the carboxyl group. B) would function only as a base because of the amino group. C) would function as neither an acid nor a base. D) would function as both an acid and a base. E) is impossible to determine how it would function.
Answer: D
25 An inhibitor of phosphodiesterase activity would have which of the following effects? A) block the response of epinephrine B) decrease the amount of cAMP in the cytoplasm C) block the activation of G proteins in response to epinephrine binding to its receptor D) prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm E) block the activation of protein kinase A
Answer: D
25 What is the major distinguishing characteristic of fungi? A) gaining nutrition through ingestion B) being sedentary C) being prokaryotic D) absorbing dissolved nutrients E) being decomposers of dead organisms
Answer: D
25 Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO₂) from one molecule of pyruvate? A) lactate B) glyceraldehydes-3-phosphate C) oxaloacetate D) acetyl CoA E) citrate
Answer: D
26 Phosphorus-32, a radioactive isotope of phosphorus-31 (atomic number 15), undergoes a form of radioactive decay whereby a neutron turns into a proton and emits radiation in the form of an electron. What is the product of such radioactive decay of phosphorus-32? A) phosphorus-31 B) a positively charged phosphorus-31 ion C) a negatively charged phosphorus-32 ion D) sulfur-32 (atomic number 16) E) the conversion of the phosphorus-32 atom into pure energy
Answer: D
26 Which modifications of fatty acids will best keep triglycerides solid at warmer temperatures? A) creating cis double bonds to the fatty acids B) adding hydrogens to the fatty acids C) creating trans double bonds to the fatty acids D) adding hydrogens and trans double bonds to the fatty acids E) adding cis double bonds and trans double bonds to the fatty acids
Answer: D
67 Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student—faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 67) Once they had determined which cells were dividing, the team wanted to use a non-radioactive method to track whether various physiological factors (such as food or body temperature) affect the action of the pathogen. Which of the following would be effective, simple, and safe? A) measuring picograms of DNA B) measuring numbers of chromosomes C) measuring numbers of chromatids D) counting the frequency of cells in mitosis E) counting newly formed plasma membranes
Answer: D
67 Which chemical group is most likely to be responsible for an organic molecule behaving as a base? A) hydroxyl B) carbonyl C) carboxyl D) amino E) phosphate
Answer: D
27 The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration.
Answer: D
27 When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? A) It is used to power yet more cellular work. B) It is used to store energy as more ATP. C) It is used to generate ADP from nucleotide precursors. D) It is lost to the environment. E) It is transported to specific organs such as the brain.
Answer: D
28 28) Generally speaking, deserts are located in places where air masses are usually A) tropical. B) humid. C) rising. D) descending. E) expanding.
Answer: D
28 28) The ratio of expressed receptor types to taste cells is A) ~10:1 B) ~100:1 C) ~1,000:1 D) 1:1 E) 1:~100
Answer: D
28 28) What causes the decrease in the amount of cyclin at a specific point in the cell cycle? A) an increase in production once the restriction point is passed B) the cascade of increased production once its protein is phosphorylated by Cdk C) the changing ratio of cytoplasm to genome D) its destruction by a process initiated by the activity of its complex with a cyclin E) the binding of PDGF to receptors on the cell surface
Answer: D
28 When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell? A) The phosphate is released as an excretory waste. B) The phosphate can only be used to regenerate more ATP. C) The phosphate can be added to water and excreted as a liquid. D) The phosphate may be incorporated into any molecule that contains phosphate. E) It enters the nucleus to affect gene expression.
Answer: D
29 29) How is it that satellites can detect differences in primary productivity on Earth? A) Photosynthetic organisms absorb more visible light in the 350—750 wavelengths. B) Satellite instruments can detect reflectance patterns of the photosynthetic organisms of different ecosystems. C) Sensitive satellite instruments can measure the amount of NADPH produced in the summative light reactions of different ecosystems. D) Satellites detect differences by comparing the wavelengths of light captured and reflected by photoautotrophs to the amount of light reaching different ecosystems. E) Satellites detect differences by measuring the amount of water vapor emitted by transpiring producers.
Answer: D
29 29) Turnover of water in temperate lakes during the spring and fall is made possible by which of the following? A) warm, less dense water layered at the top B) cold, more dense water layered at the bottom C) a distinct thermocline between less dense warm water and cold, dense water D) the changes in the density of water as seasonal temperatures change E) currents generated by nektonic animals
Answer: D
3 Singer and Nicolson's fluid mosaic model of the membrane proposed that A) membranes are a phospholipid bilayer. B) membranes are a phospholipid bilayer between two layers of hydrophilic proteins. C) membranes are a single layer of phospholipids and proteins. D) membranes consist of protein molecules embedded in a fluid bilayer of phospholipids. E) membranes consist of a mosaic of polysaccharides and proteins.
Answer: D
30 30) Which of the following causes populations to shift most quickly from an exponential to a logistic population growth? A) increased birth rate B) removal of predators C) decreased death rate D) competition for resources E) favorable climatic conditions
Answer: D
30 30) Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
Answer: D
30 P680⁺ is said to be the strongest biological oxidizing agent. Why? A) It is the receptor for the most excited electron in either photosystem. B) It is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system. C) It transfers its electrons to reduce NADP⁺ to NADPH. D) This molecule has a stronger attraction for electrons than oxygen, to obtain electrons from water. E) It has a positive charge.
Answer: D
31 Which of the following produces and modifies polysaccharides that will be secreted? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome
Answer: D
32 32) Imagine that a deep temperate zone lake did not "turn over" during the spring and fall seasons. Based on the physical and biological properties of limnetic ecosystems, what would be the difference from normal seasonal turnover? A) The lake would be uniformly cold during the winter and summer. B) The lake would fail to freeze over in winter. C) An algal bloom of algae would result every spring. D) Lakes would suffer a nutrient depletion in surface layers. E) The pH of the lake would become increasingly alkaline.
Answer: D
32 When applying the process of science, which of these is tested? A) a question B) a result C) an observation D) a prediction E) a hypothesis
Answer: D
32 Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? A) The animal cell is in a hypotonic solution, and the plant cell is in an isotonic solution. B) The animal cell is in an isotonic solution, and the plant cell is in a hypertonic solution. C) The animal cell is in a hypertonic solution, and the plant cell is in an isotonic solution. D) The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution. E) The animal cell is in a hypertonic solution, and the plant cell is in a hypotonic solution.
Answer: D
32 card image The figure above shows the structures of glucose and fructose. These two molecules are A) geometric isotopes. B) enantiomers. C) cis-trans isomers. D) structural isomers. E) nonisotopic isomers.
Answer: D
33 33) Among songbirds, a "crystallized" song is one that A) is beyond the range of human hearing. B) is perfected by juveniles. C) extremely young chicks sing. D) is a perfected species-specific song. E) warns of predators.
Answer: D
33 33) In a particular case of secondary succession, three species of wild grass all invaded a field. By the second season, a single species dominated the field. A possible factor in this secondary succession was A) equilibrium. B) facilitation. C) immigration. D) inhibition. E) parasitism.
Answer: D
33 When two atoms are equally electronegative, they will interact to form A) hydrogen bonds. B) van der Waals interactions. C) polar covalent bonds. D) nonpolar covalent bonds. E) ionic bonds.
Answer: D
34 34) The long-term problem with red-cockaded woodpecker habitat intervention in the southwest United States is A) the only habitat that can support their recovery is large tracts of mature southern pine forest. B) the mature pine forests in which they live cannot ever be subjected to forest fire. C) all of the appropriate red-cockaded woodpecker habitat has already been logged or converted to agricultural land. D) the social organization of the red-cockaded woodpecker precludes the dispersal of reproductive individuals. E) what habitat remains for the red-cockaded woodpecker does not contain trees suitable for nest-cavity construction.
Answer: D
34 In thylakoids, protons travel through ATP synthase from the thylakoid space to the stroma. Therefore, the catalytic "knobs" of ATP synthase would be located A) on the side facing the thylakoid space. B) on the ATP molecules themselves. C) on the pigment molecules of photosystem I and photosystem II. D) on the stromal side of the membrane. E) built into the center of the thylakoid stack (granum).
Answer: D
35 35) Scientists have tried raising endangered whooping cranes in captivity by using sandhill cranes as foster parents. This strategy is no longer used because A) fostered whooping crane chicks did not develop the necessary cues for migration. B) the fostered whooping cranes' critical period was variable such that different chicks imprinted on different "mothers." C) sandhill crane parents rejected their fostered whooping crane chicks soon after incubation. D) none of the fostered whooping cranes formed a mating pair-bond with another whooping crane. E) sandhill crane parents did not properly incubate whooping crane eggs.
Answer: D
35 35) When we see chiasmata under a microscope, that lets us know which of the following has occurred? A) asexual reproduction B) meiosis II C) anaphase II D) prophase I E) separation of homologs
Answer: D
36 One liter of a solution of pH 2 has how many more hydrogen ions (H⁺) than 1 L of a solution of pH 6? A) 4 times more B) 16 times more C) 40,000 times more D) 10,000 times more E) 100,000 times more
Answer: D
36 Which of the following are qualities of any good scientific hypothesis? I. It is testable. II. It is falsifiable. III. It produces quantitative data. IV. It produces results that can be replicated. A) I only B) II only C) III only D) I and II E) III and IV
Answer: D
36 Which of the following molecules contains the most polar covalent bond? A) H₂ B) O₂ C) CO₂ D) H₂O E) CH₄
Answer: D
63 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 63) What interactions exist between a "carrier crab" and "sea urchin hitch-hiker"? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: A
66 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 66) What interactions exist between a bee and a flower? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: A
68 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 68) What interactions exist between cellulose-digesting organisms in the gut of a termite and the termite? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: A
69 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 69) What interactions exist between mycorrhizae and evergreen tree roots? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: A
64 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 64) What interactions exist between the cattle egret and grazing cattle? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: B
67 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 67) What interactions exist between a tick on a dog and the dog? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: C
65 The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, - denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 65) What interactions exist between a lion pride and a hyena pack? A) +
+ B) +/o C) +/- D) o/o E) -/-/ Answer: E
37 According to the induced fit hypothesis of enzyme catalysis, which of the following is correct? A) The binding of the substrate depends on the shape of the active site. B) Some enzymes change their structure when activators bind to the enzyme. C) A competitive inhibitor can outcompete the substrate for the active site. D) The binding of the substrate changes the shape of the enzyme's active site. E) The active site creates a microenvironment ideal for the reaction.
Answer: D
34 If the pH of a solution is decreased from 9 to 8, it means that the A) concentration of H⁺ has decreased to one-tenth (1
10) what it was at pH 9. B) concentration of H⁺ has increased tenfold (10X) compared to what it was at pH 9. C) concentration of OH⁻ has increased tenfold (10X) compared to what it was at pH 9. D) concentration of OH⁻ has decreased to one-tenth (1/10) what it was at pH 9. E) concentration of H⁺ has increased tenfold (10X) and the concentration of OH⁻ has decreased to one-tenth (1/10) what they were at pH 9./ Answer: E
17 How many molecules of glucose (C₆H₁₂O₆ molecular mass = 180 daltons) would be present in 90 grams of glucose? A) 90 × 10²³ B) (6.02
180) × 10²³ C) (6.02/90) × 10²³ D) (90 x 6.02) × 10²³ E) (90/180) × 6.02 × 10²³/ Answer: E
Answer: A 13 13) Which of the following events might you predict to occur if the tilt of Earth's axis relative to its plane of orbit was increased to 33 1
2 degrees? A) Summers and winters in the United States would likely become warmer and colder, respectively. B) Winters and summers in Australia would likely become less distinct seasons. C) Seasonal variation at the equator might decrease. D) Both northern and southern hemispheres would experience summer and winter at the same time. E) Both poles would experience massive ice melts./ Answer: A
35 If the pH of a solution is increased from pH 5 to pH 7, it means that the A) concentration of H⁺ is twice (2X) what it was at pH 5. B) concentration of H⁺ is one-half (1
2) what it was at pH 5. C) concentration of OH⁻ is 100 times greater than what it was at pH 5. D) concentration of OH⁻ is one-hundredth (0.01X) what it was at pH 5. E) concentration of H⁺ is 100 times greater and the concentration of OH⁻ is one-hundredth what they were at pH 5./ Answer: C
60 card image 60) The behavior of most animals is influenced by the periods of daylight and darkness in the environment. Fiddler crabs' courtship behaviors are instead synchronized by the 29 1
2-day cycle of the moon. What is the adaptive significance of using lunar cues? A) The fiddler crab courtship ritual is highly visual so individuals need the light of the full moon to be able to observe courtship displays. B) Egg maturation in fiddler crab females takes 29 1/2 days. C) By courting at full and new moon, fiddler crabs link their reproduction to times of highest tides that disperse larvae to safer, deeper waters. D) The algae that larval fiddler crabs consume for energy and metabolism blooms on a monthly cycle, so recently hatched larvae have plenty to eat during a crucial time of their life. E) It takes about 29 days for a fiddler crab to reach sexual maturity./ Answer: C
19 19) What percent of all species on Earth are parasites? A) 1% B) 5% C) 25% D) 33 1
3% E) 50%/ Answer: D
31 What fraction of the carbon dioxide exhaled by animals is generated by the reactions of the citric acid cycle, if glucose is the sole energy source? A) 1
6 B) 1/3 C) 1/2 D) 2/3 E) 100/100/ Answer: D
14 One difference between carbon-12 (12
6 C) is that carbon-14 (14/6 C) has A) two more protons than carbon-12. B) two more electrons than carbon-12. C) two more neutrons than carbon-12. D) two more protons and two more neutrons than carbon-12. E) two more electrons and two more neutrons than carbon-12./ Answer: C
52 If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that A) the concentration of H⁺ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix. B) the concentration of H⁺ ions is tenfold higher in the mitochondrial matrix than in the cytoplasm. C) the concentration of H⁺ ions in the cytoplasm is 7
8 the concentration in the mitochondrial matrix. D) the mitochondrial matrix is more acidic than the cytoplasm. E) the concentration of H⁺ ions in the cytoplasm is 8/7 the concentration in the mitochondrial matrix./ Answer: A
9 9) Eukaryotic sexual life cycles show tremendous variation. Of the following elements, which do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores
A) I, IV, and V B) I, II, and IV C) II, III, and IV D) II, IV, and V E) I, II, III, IV, and V/ Answer: C
10 Biological evolution of life on Earth, from simple prokaryote-like cells to large, multicellar eukaryotic organisms, A) has occurred in accordance with the laws of thermodynamics. B) has caused an increase in the entropy of the planet. C) has been made possible by expending Earth's energy resources. D) has occurred in accordance with the laws of thermodynamics, by expending Earth's energy resources and causing an increase in the entropy of the planet. E) violates the laws of thermodynamics because Earth is a closed system.
Answer: A
10 Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers of 92, 94, 95, 96, 97, 98, and 100. Therefore, which of the following can be true? A) Molybdenum atoms can have between 50 and 58 neutrons. B) The isotopes of molybdenum have different electron configurations. C) The isotopes of molybdenum can have between 50 and 58 protons. D) The isotopes of molybdenum have between 50 and 58 neutrons and have different electron configurations. E) The isotopes of molybdenum have between 50 and 58 protons and have different electron configurations.
Answer: A
10 Of the following, a receptor protein in a membrane that recognizes a chemical signal is most similar to A) the active site of an allosteric enzyme that binds to a specific substrate. B) tRNA specifying which amino acids are in a polypeptide. C) a metabolic pathway operating within a specific organelle. D) an enzyme having an optimum pH and temperature for activity. E) an antibody in the immune system.
Answer: A
10 The ATP made during glycolysis is generated by A) substrate-level phosphorylation. B) electron transport. C) photophosphorylation. D) chemiosmosis. E) oxidation of NADH to NAD⁺.
Answer: A
100 Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated further, however, the ability to synthesize ATP is lost. These inside-out membrane vesicles A) will become acidic inside the vesicles when NADH is added. B) will become alkaline inside the vesicles when NADH is added. C) will make ATP from ADP and i if transferred to a pH 4 buffered solution after incubation in a pH 7 buffered solution. D) will hydrolyze ATP to pump protons out of the interior of the vesicle to the exterior. E) will reverse electron flow to generate NADH from NAD⁺ in the absence of oxygen.
Answer: A
102 Professor Jamey Marth at the University of California, Santa Barbara, identified 70 molecules that are used to build cellular macromolecules and structures. These include at least 34 saccharides, 8 nucleosides, and 20 amino acids. In theory, then, which class of biological polymer has the greatest information-coding capacity? A) polysaccharides B) proteins C) DNA D) RNA
Answer: A
104 The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the α form. Which of the following could amylase break down? A) glycogen, starch, and amylopectin B) glycogen and cellulose C) cellulose and chitin D) starch and chitin E) starch, amylopectin, and cellulose
Answer: A
104 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is A) oxygen. B) water. C) NAD⁺. D) pyruvate. E) ADP.
Answer: A
106 When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? A) The pH of the matrix increases. B) ATP synthase pumps protons by active transport. C) The electrons gain free energy. D) The cytochromes phosphorylate ADP to form ATP. E) NAD⁺ is oxidized.
Answer: A
11 11) Evidence shows that some grasses benefit from being grazed. Which of the following terms would best describe this plant-herbivore interaction? A) mutualism B) commensalism C) parasitism D) competition E) predation
Answer: A
11 11) Which of the following sets of measurements is the most useful when studying populations? A) density, dispersion, and demographics of a population B) gene frequency over time and the ratio of reproductive to nonreproductive individuals C) annual precipitation averages and mean annual temperatures D) minimum and maximum amounts of precipitation and annual temperature extremes E) ratio of predators and the number of immigrants and emigrants
Answer: A
11 Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? A) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. C) Unsaturated fatty acids are more polar than saturated fatty acids. D) The double bonds block interaction among the hydrophilic head groups of the lipids. E) The double bonds result in shorter fatty acid tails and thinner membranes.
Answer: A
11 Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP? A) It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane. B) It could activate only the epinephrine system. C) It would be able to carry out reception and transduction but would not be able to respond to a signal. D) It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane. E) It would employ a transduction pathway directly from an external messenger.
Answer: A
12 12) Statocysts contain cells that are A) mechanoreceptors which function in orientation to gravity. B) chemoreceptors used in selecting migration routes. C) photoreceptors used in setting biological rhythms. D) thermoreceptors used in prey detection. E) chemoreceptors used in acid-base balance.
Answer: A
14 The evolution of eukaryotic cells most likely involved A) endosymbiosis of an aerobic bacterium in a larger host cell-the endosymbiont evolved into mitochondria. B) anaerobic archaea taking up residence inside a larger bacterial host cell to escape toxic oxygen-the anaerobic bacterium evolved into chloroplasts. C) an endosymbiotic fungal cell evolved into the nucleus. D) acquisition of an endomembrane system, and subsequent evolution of mitochondria from a portion of the Golgi.
Answer: A
15 15) What percentage of solar radiation striking a plant is converted into chemical energy? A) 1% B) 10% C) 25% D) 50% E) 100%
Answer: A
15 Hydrophobic substances such as vegetable oil are A) nonpolar substances that repel water molecules. B) nonpolar substances that have an attraction for water molecules. C) polar substances that repel water molecules. D) polar substances that have an affinity for water. E) charged molecules that hydrogen-bond with water molecules.
Answer: A
16 16) The pathway leading to the perception of sound by mammals begins with the A) hair cells of the organ of Corti, which rests on the basilar membrane, coming in contact with the tectorial membrane. B) hair cells of the organ of Corti, which rests on the tympanic membrane, coming in contact with the tectorial membrane. C) hair cells of the organ of Corti, which rests on the tectorial membrane, coming in contact with the basilar membrane. D) hair cells of the organ of Corti coming in contact with the tectorial membrane as a result of fluid waves in the cochlea causing vibrations in the round window. E) hair cells on the tympanic membrane that stimulate the tectorial membrane neurons, leading to the auditory section of the brain.
Answer: A
16 A protein that spans the phospholipid bilayer one or more times is A) a transmembrane protein. B) an integral protein. C) a peripheral protein. D) an integrin. E) a glycoprotein.
Answer: A
16 Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question. A. operant conditioning B. agonistic behavior C. innate behavior D. imprinting E. altruistic behavior 16) Through trial and error, a rat learns to run a maze without mistakes to receive a food reward. A) A B) B C) C D) D E) E
Answer: A
16 Which of the following statements correctly describes cis-trans isomers? A) They have variations in arrangement around a double bond. B) They have an asymmetric carbon that makes them mirror images. C) They have the same chemical properties. D) They have different molecular formulas. E) Their atoms and bonds are arranged in different sequences.
Answer: A
17 17) The cochlea is an organ of auditory transduction that contains A) fluid and cells that can undergo mechanosensory transduction. B) air and cells that produce wax. C) air and small bones that vibrate in response to sound waves. D) fluid with stacks of chemosensory cells. E) air and statocysts activated by movement.
Answer: A
17 Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that A) an electron may move to an electron shell farther away from the nucleus. B) an electron may move to an electron shell closer to the nucleus. C) the atom may become a radioactive isotope. D) the atom would become a positively charged ion, or cation, and become a radioactive isotope. E) the atom would become a negatively charged ion, or anion.
Answer: A
18 18) As climate changes because of global warming, species' ranges in the northern hemisphere may move northward, using effective reproductive adaptations to disperse their seeds. The trees that are most likely to avoid extinction in such an environment are those that A) have seeds that are easily dispersed by wind or animals. B) have thin seed coats. C) produce well-provisioned seeds. D) have seeds that become viable only after a forest fire. E) disperse many seeds in close proximity to the parent tree.
Answer: A
18 18) If a cell has completed the first meiotic division and is just beginning meiosis II, which of the following is an appropriate description of its contents? A) It has half the amount of DNA as the cell that began meiosis. B) It has the same number of chromosomes but each of them has different alleles than another cell from the same meiosis. C) It has half the chromosomes but twice the DNA of the originating cell. D) It has one-fourth the DNA and one-half the chromosomes as the originating cell. E) It is identical in content to another cell from the same meiosis.
Answer: A
18 What does the chemiosmotic process in chloroplasts involve? A) establishment of a proton gradient across the thylakoid membrane B) diffusion of electrons through the thylakoid membrane C) reduction of water to produce ATP energy D) movement of water by osmosis into the thylakoid space from the stroma E) formation of glucose, using carbon dioxide, NADPH, and ATP
Answer: A
19 19) Generalized global air circulation and precipitation patterns are caused by A) rising, warm, moist air masses that cool and release precipitation as they rise and then, at high altitude, cool and sink back to the surface as dry air masses after moving north or south of the tropics. B) air masses that are dried and heated over continental areas that rise, cool aloft, and descend over oceanic areas followed by a return flow of moist air from ocean to land, delivering high amounts of precipitation to coastal areas. C) polar, cool, moist high-pressure air masses from the poles that move along the surface, releasing precipitation along the way to the equator where they are heated and dried. D) the revolution of Earth around the sun. E) mountain ranges that deflect air masses containing variable amounts of moisture.
Answer: A
19 In general, a signal transmitted via phosphorylation of a series of proteins A) brings a conformational change to each protein. B) requires binding of a hormone to a cytosol receptor. C) cannot occur in yeasts because they lack protein phosphatases. D) requires phosphorylase activity. E) allows target cells to change their shape and therefore their activity.
Answer: A
2 2) In ecosystems, why is the term cycling used to describe material transfer, whereas the term flow is used for energy exchange? A) Materials are repeatedly used, but energy flows through and out of ecosystems. B) Both material and energy are recycled and are then transferred to other ecosystems as in a flow. C) Materials are cycled into ecosystems from other ecosystems, but energy constantly flows within the ecosystem. D) Both material and energy flow in a never-ending stream within an ecosystem. E) None of the choices is correct.
Answer: A
2 2) The human genome is minimally contained in which of the following? A) every human cell B) each human chromosome C) the entire DNA of a single human D) the entire human population E) each human gene
Answer: A
2 The complexity and variety of organic molecules is due to A) the chemical versatility of carbon atoms. B) the variety of rare elements in organic molecules. C) the fact that they can be synthesized only in living organisms. D) their interaction with water. E) their tremendously large sizes.
Answer: A
20 20) During which phase of mitosis do the chromatids become chromosomes? A) telophase B) anaphase C) prophase D) metaphase E) cytokinesis
Answer: A
20 20) The sand grains or other dense materials resting on mechanoreceptors used by most invertebrates to sense gravity are called A) cochlea. B) statoliths. C) stapes. D) pinnae. E) antennae.
Answer: A
20 20) Which of the following might result in a human zygote with 45 chromosomes? A) an error in either egg or sperm meiotic anaphase B) failure of the egg nucleus to be fertilized by the sperm C) fertilization of a 23 chromosome human egg by a 22 chromosome sperm of a closely related species D) an error in the alignment of chromosomes on the metaphase plate E) lack of chiasmata in prophase I
Answer: A
20 A chemical reaction that has a positive ΔG is correctly described as A) endergonic. B) endothermic. C) enthalpic. D) spontaneous. E) exothermic.
Answer: A
21 21) Of the following ecosystem types, which have been impacted the most by humans? A) wetland and riparian B) open and benthic ocean C) desert and high alpine D) taiga and second-growth forests E) tundra and arctic
Answer: A
21 21) Which of the following was a discovery that had to be made before human chromosomes could be correctly counted? A) how to use a hypotonic solution to swell nuclei B) how to visualize sperm nuclei C) how to visualize chromosomes D) when to see chromosomes separate from one another E) when to see chromosomes in pairs
Answer: A
22 22) Which of the following is true about imprinting? A) It may be triggered by visual or chemical stimuli. B) It happens to many adult animals, but not to their young. C) It is a type of learning that does not involve innate behavior. D) It occurs only in birds. E) It causes behaviors that last for only a short time (the sensitive period).
Answer: A
22 The toxin of Vibrio cholerae causes profuse diarrhea because it A) modifies a G protein involved in regulating salt and water secretion. B) decreases the cytosolic concentration of calcium ions, making the cells hypotonic. C) binds with adenylyl cyclase and triggers the formation of cAMP. D) signals IP3 to act as a second messenger for the release of calcium. E) modifies calmodulin and activates a cascade of protein kinases.
Answer: A
22 Which of the following statements is true for the class of biological molecules known as lipids? A) They are insoluble in water. B) They are made from glycerol, fatty acids, and phosphate. C) They contain less energy than proteins and carbohydrates. D) They are made by dehydration reactions. E) They contain nitrogen.
Answer: A
23 23) Which of the following can be said about light in aquatic environments? A) Water selectively reflects and absorbs certain wavelengths of light. B) Photosynthetic organisms that live in deep water probably use red light. C) Longer wavelengths penetrate to greater depths. D) Light penetration seldom limits the distribution of photosynthetic species. E) Most photosynthetic organisms avoid the surface where the light is too intense.
Answer: A
23 Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom? A) 1 B) 3 C) 0 D) 7 E) 9
Answer: A
23 The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? (Hint: What is the mass of 1 liter of pure water?) A) 55.6 M B) 18 M C) 37 M D) 0.66 M E) 1.0 M
Answer: A
23 Where are the molecules of the electron transport chain found in plant cells? A) thylakoid membranes of chloroplasts B) stroma of chloroplasts C) outer membrane of mitochondria D) matrix of mitochondria E) cytoplasm
Answer: A
23 Which structure is the site of the synthesis of proteins that may be exported from the cell? A) rough ER B) lysosomes C) plasmodesmata D) Golgi vesicles E) free cytoplasmic ribosomes
Answer: A
24 24) Which of the following is a type of research in which a conservation biologist would be involved? A) reestablishing whooping cranes in their former breeding grounds in North Dakota B) studying species diversity and interaction in the Florida Everglades, past and present C) studying population ecology of grizzly bears in Yellowstone National Park D) determining the effects of hunting white-tailed deer in Vermont E) determining the effect of protection programs on the recovery of the North Atlantic cod fishery
Answer: A
24 Which of the following most likely would be an immediate result of growth factor binding to its receptor? A) protein kinase activity B) adenylyl cyclase activity C) GTPase activity D) protein phosphatase activity E) phosphorylase activity
Answer: A
25 25) Elephants are not the most dominant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following describes why elephants are the keystone species in this scenario? A) Essentially all of the other species depend on the presence of the elephants to maintain the community. B) Grazing animals depend upon the elephants to convert forests to grassland. C) Elephants prevent drought in African grasslands. D) Elephants are the biggest herbivore in this community. E) Elephants help other populations survive by keeping out many of the large African predators.
Answer: A
25 A strong acid like HCl A) ionizes completely in an aqueous solution. B) increases the pH when added to an aqueous solution. C) reacts with strong bases to create a buffered solution. D) is a strong buffer at low pH. E) both ionizes completely in aqueous solutions and is a strong buffer at low pH.
Answer: A
25 Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement? A) a steroid B) cellulose C) DNA D) an enzyme E) a contractile protein
Answer: A
26 26) Which of the following happens at the conclusion of meiosis I? A) Homologous chromosomes are separated. B) The chromosome number per cell is conserved. C) Sister chromatids are separated. D) Four daughter cells are formed. E) The sperm cells elongate to form a head and a tail end.
Answer: A
26 26) You have the technology necessary to measure each of the following in a sample of animal cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity. Which would you expect to increase significantly from M to G₁? A) organelle density and enzymatic activity B) cell wall components and DNA C) chlorophyll and cell walls D) organelle density and cell walls E) chlorophyll and DNA
Answer: A
26 Nitrous oxide gas molecules diffusing across a cell's plasma membrane is an example of A) diffusion across the lipid bilayer. B) facilitated diffusion. C) active transport. D) osmosis. E) cotransport.
Answer: A
26 Reduction of NADP⁺ occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration.
Answer: A
26 What are archaea? A) Prokaryotes characterized as extremophiles that share some bacterial and some eukaryotic traits. B) Organisms that are adapted to high temperature environments, such as in volcanic springs. C) Single-celled organisms that are killed by the application of antibiotics at certain concentrations. D) Bacteria-like organisms that can live only in extreme salt environments. E) Primitive protist-like creatures possessing fewer than two chromosomes per cell.
Answer: A
27 27) In models of logistic population growth, A) the population growth rate slows dramatically as N approaches K. B) new individuals are added to the population most rapidly at the beginning of the population's growth. C) new individuals are added to the population as N approaches K. D) only density-dependent factors affect the rate of population growth. E) carrying capacity is never reached.
Answer: A
27 A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance? A) It is a strong acid that ionizes completely in water. B) It is a strong base that ionizes completely in water. C) It is a weak acid. D) It is a weak base. E) It is neither an acid nor a base.
Answer: A
27 How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate? A) two B) four C) six D) eight E) ten
Answer: A
27 Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? A) CO₂ B) an amino acid C) glucose D) K⁺ E) starch
Answer: A
28 28) A stickleback fish will attack a fish model as long as the model has red coloring. What animal behavior idea is manifested by this observation? A) sign stimulus B) cognition C) imprinting D) classical conditioning E) operant conditioning
Answer: A
28 28) Biomanipulation can best be described as A) removing many of the next higher trophic level organisms so that the struggling trophic level below can recover. B) a means of reversing the effects of pollution by applying antidote chemicals that have a neutralizing effect on the community. C) an example of how one would use the bottom-up model for community restoration. D) adjusting the numbers of each of the trophic levels back to the numbers that they were before human disturbance. E) monitoring and adjusting the nutrient and energy flow through a community with new technologies.
Answer: A
28 28) The Allee effect is used to describe a population that A) has become so small that it will have difficulty surviving and reproducing. B) has become so large that it will have difficulty surviving and reproducing. C) is viable and stable at its carrying capacity. D) has exceeded its carrying capacity. E) is in crash decline.
Answer: A
29 ) The bonding of two amino acid molecules to form a larger molecule requires A) the release of a water molecule. B) the release of a carbon dioxide molecule. C) the addition of a nitrogen atom. D) the addition of a water molecule. E) the release of a nitrous oxide molecule.
Answer: A
29 29) Imagine five forest communities, each with 100 individuals distributed among four different tree species (W, X, Y, and Z). Which forest community would be most diverse? A) 25W, 25X, 25Y, 25Z B) 40W, 30X, 20Y, 10Z C) 50W, 25X, 15Y, 10Z D) 70W, 10X, 10Y, 10Z E) 100W, 0X, 0Y, 0Z
Answer: A
29 29) Parental protective behavior in turkeys is triggered by the cheeping sound of young chicks. What term best applies to this behavior? A) sign stimulus B) cognition C) imprinting D) classical conditioning E) operant conditioning
Answer: A
29 29) Which of the following is released by platelets in the vicinity of an injury? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
Answer: A
29 A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of his condition? A) His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. B) His cells cannot move NADH from glycolysis into the mitochondria. C) His cells contain something that inhibits oxygen use in his mitochondria. D) His cells lack the enzyme in glycolysis that forms pyruvate. E) His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA.
Answer: A
29 Why is the theme of evolution considered to be the core theme of biology by biologists? A) It provides a framework within which all biological investigation makes sense. B) It is recognized as the core theme of biology by organizations such as the National Science Foundation. C) Controversy about this theory provides a basis for a great deal of experimental research. D) Since it cannot be proven, biologists will be able to study evolutionary possibilities for many years. E) Biologists do not subscribe to alternative models.
Answer: A
29 card image Which of the following people used this apparatus to study the formation of organic compounds? A) Stanley Miller B) Jakob Berzelius C) Friedrich Wohler D) Hermann Kolbe E) August Kekulé
Answer: A
3 3) In the human species, all somatic cells have 46 chromosomes. Which of the following can also be true? A) A plant species (privet shrubs) has 46 chromosomes per cell. B) Some adult humans have 69 chromosomes per cell. C) Some adult humans have 23 chromosomes per cell. D) A certain fungal species has only one chromosome per cell. E) A certain bacterial species has 23 chromosomes.
Answer: A
3 The main source of energy for producers in an ecosystem is A) light energy B) kinetic energy C) thermal energy D) chemical energy E) ATP
Answer: A
3 When electrons move closer to a more electronegative atom, what happens? A) The more electronegative atom is reduced, and energy is released. B) The more electronegative atom is reduced, and energy is consumed. C) The more electronegative atom is oxidized, and energy is consumed. D) The more electronegative atom is oxidized, and energy is released. E) The more electronegative atom is reduced, and entropy decreases.
Answer: A
3 Which of the following is a likely explanation of why natural selection favored the evolution of signals for sexual reproduction? A) Even in the simplest organisms, sexual reproduction required several coordinated responses by cells. B) Multicellular eukaryotes required signals that were responded to by multiple organ systems. C) Cells of several kinds of mating types needed to sort themselves to allow self-recognition. D) Rooted plants required chemical diffusible signals that could travel throughout the organism. E) Hormones required a mechanism for introducing changes in their target tissues.
Answer: A
3 Which of the following is a statement of the first law of thermodynamics? A) Energy cannot be created or destroyed. B) The entropy of the universe is decreasing. C) The entropy of the universe is constant. D) Kinetic energy is stored energy that results from the specific arrangement of matter. E) Energy cannot be transferred or transformed.
Answer: A
30 30) Which of the following lists of organisms is ranked in correct order from lowest to highest percent in production efficiency? A) mammals, fish, insects B) insects, fish, mammals C) fish, insects, mammals D) insects, mammals, fish E) mammals, insects, fish
Answer: A
30 What is the pH of a solution with a hydroxyl ion [OH⁻] concentration of 10⁻¹² M? A) pH 2 B) pH 4 C) pH 10 D) pH 12 E) pH 14
Answer: A
31 31) Which of the following is responsible for the differences in summer and winter temperature stratification of deep temperate zone lakes? A) Water is densest at 4°C. B) Oxygen is most abundant in deeper waters. C) Winter ice sinks in the summer. D) Stratification is caused by a thermocline. E) Stratification always follows the fall and spring turnovers.
Answer: A
31 31) Which term do ecologists use to describe the ability of a community either to resist change or to recover to its original state after change? A) stability B) succession C) partitioning D) productivity E) competitive exclusion
Answer: A
31 Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater? A) Water will leave the cells, causing them to shrivel and collapse. B) NaCl will be exported from the red blood cells by facilitated diffusion. C) The blood cells will take up water, swell, and eventually burst. D) NaCl will passively diffuse into the red blood cells. E) The blood cells will expend ATP for active transport of NaCl into the cytoplasm.
Answer: A
31 The bonding of two amino acid molecules to form a larger molecule requires which of the following? A) removal of a water molecule B) addition of a water molecule C) formation of a glycosidic bond D) formation of a hydrogen bond E) both removal of a water molecule and formation of a hydrogen bond
Answer: A
31 Which of the following statements is true about enzyme-catalyzed reactions? A) The reaction is faster than the same reaction in the absence of the enzyme. B) The free energy change of the reaction is opposite from the reaction that occurs in the absence of the enzyme. C) The reaction always goes in the direction toward chemical equilibrium. D) Enzyme-catalyzed reactions require energy to activate the enzyme. E) Enzyme-catalyzed reactions release more free energy than noncatalyzed reactions.
Answer: A
32 Which of the following solutions would require the greatest amount of base to be added to bring the solution to neutral pH? A) gastric juice at pH 2 B) vinegar at pH 3 C) tomato juice at pH 4 D) black coffee at pH 5 E) household bleach at pH 12
Answer: A
32 electron flow may be photoprotective (protective to light-induced damage). Which of the following experiments could provide information on this phenomenon? A) use mutated organisms that can grow but that cannot carry out cyclic flow of electrons and compare their abilities to photosynthesize in different light intensities against those of wild-type organisms B) use plants that can carry out both linear and cyclic electron flow, or only one or another of these processes, and compare their light absorbance at different wavelengths and different light intensities C) use bacteria that have only cyclic flow and look for their frequency of mutation damage at different light intensities D) use bacteria with only cyclic flow and measure the number and types of photosynthetic pigments they have in their membranes E) use plants with only photosystem I operative and measure how much damage occurs at different wavelengths
Answer: A
33 33) The primary difference between the small-population approach (S-PA) and the declining-population approach (D-PA) to biodiversity recovery is A) S-PA is interested in bolstering the genetic diversity of a threatened population rather than the environmental factors that caused the population's decline. B) S-PA kicks in for conservation biologists when population numbers fall below 500. C) D-PA would likely involve bringing together individuals from scattered small populations to interbreed in order to promote genetic diversity. D) S-PA would investigate and eliminate all of the human impacts on the habitat of the species being studied for recovery. E) D-PA would use recently collected population data to calculate an extinction vortex.
Answer: A
33 One inhibitor of cGMP is Viagra. It provides a signal that leads to dilation of blood vessels and increase of blood in the penis, facilitating erection. Since cGMP is inhibited, the signal is prolonged. The original signal that is now inhibited would have A) hydrolyzed cGMP to GMP. B) hydrolyzed GTP to GDP. C) phosphorylated GDP. D) dephosphorylated cGMP. E) removed GMP from the cell.
Answer: A
34 34) How does inefficient transfer of energy among trophic levels result in the typically high endangerment status of many top-level predators? A) Top-level predators are destined to have small populations that are sparsely distributed. B) Predators have relatively large population sizes. C) Predators are more disease-prone than animals at lower trophic levels. D) Predators have short life spans and short reproductive periods. E) Top-level predators are more likely to be stricken with parasites.
Answer: A
34 34) If you are interested in observing a relatively simple community structure in a clear water lake, you would do well to choose diving into A) an oligotrophic lake. B) a eutrophic lake. C) a relatively shallow lake. D) a nutrient-rich lake. E) a lake with consistently warm temperatures.
Answer: A
35 35) The MPF protein complex turns itself off by A) activating a process that destroys cyclin components. B) activating an enzyme that stimulates cyclin. C) binding to chromatin. D) exiting the cell. E) activating the anaphase-promoting complex.
Answer: A
35 35) Why do moderate levels of disturbance result in an increase in community diversity? A) Habitats are opened up for less competitive species. B) Competitively dominant species infrequently exclude less competitive species after a moderate disturbance. C) The environmental conditions become optimal. D) The resulting uniform habitat supports stability, which in turn supports diversity. E) Less-competitive species evolve strategies to compete with dominant species.
Answer: A
35 A covalent bond is likely to be polar when A) one of the atoms sharing electrons is much more electronegative than the other atom. B) the two atoms sharing electrons are equally electronegative. C) oxygen is one of the two atoms sharing electrons. D) one of the atoms has absorbed more energy than the other atom. E) the two atoms sharing electrons are different elements.
Answer: A
35 The application of scientific knowledge for some specific purpose is known as A) technology. B) deductive science. C) inductive science. D) anthropologic science. E) pure science.
Answer: A
36 36) If a meteor impact or volcanic eruption injected a lot of dust into the atmosphere and reduced the sunlight reaching Earth's surface by 70% for one year, which of the following marine communities most likely would be least affected? A) deep-sea vent B) coral reef C) intertidal D) pelagic E) estuary
Answer: A
36 36) Which of the following is characteristic of K-selected populations? A) offspring with good chances of survival B) many offspring per reproductive episode C) small offspring D) a high intrinsic rate of increase E) early parental reproduction
Answer: A
36 In a cyanobacterium, the reactions that produce NADPH occur in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but is not part of photosynthesis.
Answer: A
37 37) In the human retina A) cone cells can detect color, but rod cells cannot. B) cone cells are more sensitive than rod cells to light. C) cone cells, but not rod cells, have a visual pigment. D) rod cells are most highly concentrated in the center of the retina. E) rod cells require higher illumination for stimulation than do cone cells.
Answer: A
37 37) Which variables define the ecological life history of a species? A) the age at which reproduction begins, frequency of reproduction, and the number of offspring for each reproductive episode B) the ratio of females to males, the length of the breeding season, and the number of offspring for each reproductive episode C) the number of offspring produced over a lifetime by a breeding pair and the survivability of the offspring D) timing breeding sessions with optimal environmental conditions and the number of offspring produced during each breeding session E) the amount of parental care given after birth, the number of reproductive episodes per year, and the number of years females are capable of producing viable offspring
Answer: A
37 37) White-crowned sparrows can only learn the "crystallized" song for their species by A) listening to adult sparrow songs during a sensitive period as a fledgling, followed by a practice period until the juvenile matches its melody to its memorized fledgling song. B) listening to the song of its own species during a critical period so that it will imprint to its own species song and not the songs of other songbird species. C) practicing as a fledgling until the innate species-specific song becomes perfected. D) performing the crystallized song as adults when they become sexually mature, as the song is programmed into the innate behavior for the species. E) observing and practicing after receiving social confirmation from other adults at a critical period during their first episode of courtship behavior.
Answer: A
37 What explains the increased concentration of Ca⁺⁺ in the ER? A) Calcium ions are actively imported from the cytoplasm into the ER. B) Calcium concentration is kept low in the cytoplasm because of its high usage level. C) Calcium cannot enter the plasma membrane through ion channels. D) Calcium levels in the blood or other body fluids are extremely low. E) The Ca ions are recycled from other molecules in the ER.
Answer: A
37 When a hypothesis cannot be written in an "If...then" format, what does this mean? A) It does not represent deductive reasoning. B) It cannot be a scientific hypothesis. C) The subject cannot be explored scientifically. D) The hypothesizer does not have sufficient information. E) It cannot be testable.
Answer: A
37 Which bonds are created during the formation of the primary structure of a protein? A) peptide bonds B) hydrogen bonds C) disulfide bonds D) phosphodiester bonds E) peptide bonds, hydrogen bonds, and disulfide bonds
Answer: A
38 38) A community's actual evapotranspiration is a reflection of A) solar radiation, temperature, and water availability. B) the number of plants and how much moisture they lose. C) the depth of the water table. D) wind speed and the frequency of wind gusts. E) plant biomass and plant water content.
Answer: A
39 39) The blind spot in the human retina is the location that has the collected axons of A) ganglion cells. B) bipolar cells. C) primary visual cortex. D) optic chiasma. E) lateral geniculate nuclei.
Answer: A
39 39) What probably explains why coastal and inland garter snakes react differently to banana slug prey? A) Ancestors of coastal snakes that could eat the abundant banana slugs had increased fitness. No such selection occurred inland, where banana slugs were absent. B) Banana slugs are camouflaged, and inland snakes, which have poorer vision than coastal snakes, are less able to see them. C) Garter snakes learn about prey from other garter snakes. Inland garter snakes have fewer types of prey because they are less social. D) Inland banana slugs are distasteful, so inland snakes learn to avoid them. Coastal banana slugs are palatable to garter snakes. E) Garter snakes learn to eat what their mother eats. Coastal snake mothers happened to prefer slugs.
Answer: A
39 For the following question, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II 39) Synaptonemal complexes form or are still present. A) I only B) I and IV only C) I and VIII only D) II and VI only E) I, II, III, and IV only
Answer: A
39 In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic pumps present in the membrane. The gradients of the other ions are most likely accounted for by A) cotransport proteins. B) ion channels. C) carrier proteins. D) passive diffusion across the plasma membrane. E) cellular metabolic reactions that create or destroy ions.
Answer: A
4 Where does the Calvin cycle take place? A) stroma of the chloroplast B) thylakoid membrane C) cytoplasm surrounding the chloroplast D) interior of the thylakoid (thylakoid space) E) outer membrane of the chloroplast
Answer: A
40 40) An injury to the occipital lobe will likely impair function of the A) primary visual cortex. B) thalamus. C) optic chiasma. D) sense of taste. E) sense of touch.
Answer: A
40 40) Which of the following statements about evolution of behavior is correct? A) Natural selection will favor behavior that enhances survival and reproduction. B) An animal may show behavior that minimizes reproductive fitness. C) If a behavior is less than optimal, it will eventually become optimal through natural selection. D) Innate behaviors can never be altered by natural selection. E) All of the statements are correct.
Answer: A
40 Where do the enzymatic reactions of the Calvin cycle take place? A) stroma of the chloroplast B) thylakoid membranes C) matrix of the mitochondria D) cytosol around the chloroplast E) thylakoid space
Answer: A
41 41) In the development of terrestrial biomes, which factor is most dependent on all the others? A) the species of colonizing animals B) prevailing temperature C) prevailing rainfall D) mineral nutrient availability E) soil structure
Answer: A
41 One of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO₃⁻ and a hydrogen ion (H⁺). Thus, H₂CO₃ ↔ HCO₃⁻ + H⁺ If the pH of the blood increases, one would expect A) a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻. B) an increase in the concentration of H₂CO₃ and a decrease in the concentration of HCO₃⁻. C) a decrease in the concentration of HCO₃⁻ and an increase in the concentration of H⁺. D) an increase in the concentration of HCO₃⁻ and a decrease in the concentration of OH⁻. E) a decrease in the concentration of HCO₃⁻ and an increase in the concentration of both HH₂CO₃ and H⁺.
Answer: A
42 42) How does the sexual life cycle increase the genetic variation in a species? A) by allowing crossing over B) by allowing fertilization C) by increasing gene stability D) by conserving chromosomal gene order E) by decreasing mutation frequency
Answer: A
42 Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake? A) 1 × 10⁻¹⁰ mol of hydroxyl ion per liter of lake water B) 1 × 10⁻⁴ mol of hydroxyl ion per liter of lake water C) 10.0 M with regard to hydroxyl ion concentration D) 4.0 M with regard to hydroxyl ion concentration E) 1 × 10⁻⁴ mol of hydroxyl ion per liter of lake water and 4.0 M with regard to hydrogen ion concentration
Answer: A
42 Which bond or interaction would be difficult to disrupt when compounds are put into water? A) covalent bond B) hydrogen bond C) van der Waals interaction D) ionic bond E) either covalent bonds or ionic bonds
Answer: A
43 43) Consider the food chain grass → grasshopper → mouse → snake → hawk. How much of the chemical energy fixed by photosynthesis of the grass (100%) is available to the hawk? A) 0.01% B) 0.1% C) 1% D) 10% E) 60%
Answer: A
43 Some of the drugs used to treat HIV patients are competitive inhibitors of the HIV reverse transcriptase enzyme. Unfortunately, the high mutation rate of HIV means that the virus rapidly acquires mutations with amino acid changes that make them resistant to these competitive inhibitors. Where in the reverse transcriptase enzyme would such amino acid changes most likely occur in drug-resistant viruses? A) in or near the active site B) at an allosteric site C) at a cofactor binding site D) in regions of the protein that determine packaging into the virus capsid E) such mutations could occur anywhere with equal probability
Answer: A
44 44) Independent assortment of chromosomes is a result of A) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. B) the random nature of the fertilization of ova by sperm. C) the random distribution of the sister chromatids to the two daughter cells during anaphase II. D) the relatively small degree of homology shared by the X and Y chromosomes. E) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I, the random nature of the fertilization of ova by sperm, the random distribution of the sister chromatids to the two daughter cells during anaphase II, and the relatively small degree of homology shared by the X and Y chromosomes.
Answer: A
44 44) Which of the following is true about "hot spots"? A) One-third of all species on Earth occupy less than 1.5% of Earth's land area (hot spots). B) All of the plants and animals containing genes that may be useful to humankind are located in Earth's hot spots. C) Around 75% of all of the undiscovered species of organisms live in ecological hot spots. D) As conservation measures improve over the next ten years, hot spots will likely disappear. E) The hot spots that are in most dire need of remediation are located in the tundra.
Answer: A
38 38) Imagine that you are designing an experiment aimed at determining whether the initiation of migratory behavior is largely under genetic control. Of the following options, the best way to proceed is to A) observe genetically distinct populations in the field and see if they have different migratory habits. B) perform within-population matings with birds from different populations that have different migratory habits. Do this in the laboratory and see if offspring display parental migratory behavior. C) bring animals into the laboratory and determine the conditions under which they become restless and attempt to migrate. D) perform within-population matings with birds from different populations that have different migratory habits. Rear the offspring in the absence of their parents and observe the migratory behavior of offspring. E) All of the options are equally productive ways to approach the question.
Answer: D
38 38) Receptor proteins for the neurotransmitter molecules released by rods and cones are found on A) ganglion cells. B) horizontal cells. C) amacrine cells. D) bipolar cells. E) lateral cells.
Answer: D
38 In a plant cell, DNA may be found A) only in the nucleus. B) only in the nucleus and mitochondria. C) only in the nucleus and chloroplasts. D) in the nucleus, mitochondria, and chloroplasts. E) in the nucleus, mitochondria, chloroplasts, and peroxisomes.
Answer: D
38 In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? A) energy released as electrons flow through the electron transport system B) energy released from substrate-level phosphorylation C) energy released from movement of protons through ATP synthase, against the electrochemical gradient D) energy released from movement of protons through ATP synthase, down the electrochemical gradient E) No external source of energy is required because the reaction is exergonic.
Answer: D
39 39) Species introduced by humans to new geographic locations A) are usually successful in colonizing the area. B) always spread because they encounter none of their natural predators. C) increase the diversity and therefore the stability of the ecosystem. D) can outcompete and displace native species for biotic and abiotic resources. E) are always considered pests by ecologists.
Answer: D
39 39) Why do tropical communities tend to have greater species diversity than temperate or polar communities? A) They are less likely to be affected by human disturbance. B) There are fewer parasites to negatively affect the health of tropical communities. C) Tropical communities are low in altitude, whereas temperate and polar communities are high in altitude. D) Tropical communities are generally older than temperate and polar communities. E) More competitive dominant species have evolved in temperate and polar communities.
Answer: D
39 In ammonium chloride salt (NH₄Cl) the anion is a single chloride ion, Cl. What is the cation of NH₄Cl? A) N, with a charge of +1 B) NH, with a charge of +1 C) H₃, with a charge of +1 D) NH₄, with a charge of +1 E) NH₄, with a charge of +4
Answer: D
39 The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. In light of the endosymbiont theory for the evolutionary origin of mitochondria, where is most ATP synthesis likely to occur in prokaryotic cells? A) in the cytoplasm B) on the inner mitochondrial membrane C) on the endoplasmic reticulum D) on the plasma membrane E) on the inner nuclear envelope
Answer: D
39 card image 39) Often the growth cycle of one population has an effect on the cycle of another. As moose populations increase, for example, wolf populations also increase. Thus, if we are considering the logistic equation for the wolf population, SEE IMAGE which of the factors accounts for the effect on the moose population? A) r B) N C) rN D) K E) dt
Answer: D
39 card image What is the name of the functional group shown in the figure above? A) carbonyl B) ketone C) aldehyde D) carboxyl E) hydroxyl
Answer: D
44 44) Which of the following studies would shed light on the mechanism of spread of H5N1 from Asia? A) Perform cloacal or saliva smears of migrating waterfowl to monitor whether any infected birds show up in Alaska. B) Test fecal samples for H5N1 in Asian waterfowl that live near domestic poultry farms in Asia. C) Test for the presence of H5N1 in poultry used for human consumption worldwide. D) Locate and destroy birds infected with H5N1 in Asian open-air poultry markets. E) Keep domestic and wild fowl from interacting with each other to minimize the probability that wild fowl could get infected and migrate out of Asia.
Answer: A
44 44) You discover a rare new bird species, but you are unable to observe its mating behavior. You see that the male is large and ornamental compared with the female. On this basis, you can probably conclude that the species is A) polygamous. B) monogamous. C) polyandrous. D) promiscuous. E) agonistic.
Answer: A
44 The NADPH required for the Calvin cycle comes from A) reactions initiated in photosystem I. B) reactions initiated in photosystem II. C) the citric acid cycle. D) glycolysis. E) oxidative phosphorylation.
Answer: A
44 card image Which functional group shown above is characteristic of alcohols? A) A B) B C) C D) D E) E
Answer: A
45 The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? A) It will be on the cytoplasmic side of the ER. B) It will be on the side facing the interior of the ER. C) It could be facing in either direction because proteins are properly reoriented in the Golgi apparatus. D) It doesn't matter, because the pump is not active in the ER.
Answer: A
46 46) The use of DDT as an insecticide in the United States has been outlawed since 1971, yet is still a problem for certain top-level carnivores in the United States. Which of the following choices best explains this apparent incongruity? A) DDT is still used for mosquito control in tropical countries, and certain migratory predators can be affected by a seasonal biomagnification. B) DDT is persistent in the environment and all of the pre-1971 DDT is still available in toxic form to poison top-level carnivores. C) Pre-1971 DDT has been deposited in certain habitats, particularly wetlands and estuaries, so predators in these ecosystems are vulnerable to biomagnifications of DDT. D) Whereas most DDT-susceptible species have become resistant to persistent DDT, others are still vulnerable. E) All of the options are correct.
Answer: A
46 Carbon dioxide (CO₂) is readily soluble in water, according to the equation CO₂ + H₂O ↔ H₂CO₃. Carbonic acid (H₂CO₃) is a weak acid. Respiring cells release CO₂ into the bloodstream. What will be the effect on pH of blood as that blood first comes in contact with respiring cells? A) Blood pH will decrease slightly. B) Blood pH will increase slightly. C) Blood pH will remain unchanged. D) Blood pH will first increase, then decrease as CO₂ combines with hemoglobin. E) Blood pH will first decrease, then increase sharply as CO₂ combines with hemoglobin.
Answer: A
46 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? A) The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP⁺ to the light reactions. B) The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. C) The light reactions supply the Calvin cycle with CO₂ to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. D) The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. E) There is no relationship between the light reactions and the Calvin cycle.
Answer: A
47 Use the following information to answer questions 47 - 50. Golden algae are a group of protists whose color is due to carotenoid pigments: yellow and brown. Most have two flagella and all are photosynthetic. A group of students was given a significant sample of one of these (Dinobryon) that is colonial. Their instructions for the project were to design two or more experiments that could be done with these organisms. Since these organisms are protists, which of these characteristics could the students assume to be true? A) The organisms are photosynthetic. B) All of them are marine. C) They are single-celled. D) They lack membrane-bound organelles. E) Each has a single circular molecule of DNA.
Answer: A
47 47) At the M phase checkpoint, the complex allows for what to occur? A) Separase enzyme cleaves cohesins and allows chromatids to separate. B) Cohesins alter separase to allow chromatids to separate. C) Kinetochores are able to bind to spindle microtubules. D) All microtubules are made to bind to kinetochores. E) Daughter cells are allowed to pass into G₁.
Answer: A
47 Movement of vesicles within the cell depends on what cellular structures? A) microtubules and motor proteins B) actin filaments and microtubules C) actin filaments and ribosomes D) centrioles and motor proteins E) actin filaments and motor proteins
Answer: A
47 card image 47) Which of the life cycles is typical for animals? A) I only B) II only C) III only D) I and II E) I and III
Answer: A
48 48) The calcium ions released into the cytosol during excitation of skeletal muscle bind to A) troponin. B) tropomyosin. C) actin. D) myosin. E) transverse tubules.
Answer: A
48 In C. elegans, ced-9 prevents apoptosis in a normal cell in which of the following ways? A) It prevents the caspase activity of ced-3 and ced-4. B) Ced-9 remains inactive until it is signaled by ced-3 and other caspases. C) Ced-9 cleaves to produce ced-3 and ced-4. D) Ced-9 enters the nucleus and activates apoptotic genes. E) Ced-9 prevents blebbing by its action on the cell membrane.
Answer: A
49 49) This causes an increase in the intensity of UV radiation reaching Earth. A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: A
49 49) Which of the following best describes "game theory" as it applies to animal behavior? A) The fitness of a particular behavior is influenced by other behavioral phenotypes in a population. B) The total of all of the behavioral displays, both male and female, is related to courtship. C) An individual in a population changes a behavioral phenotype to gain a competitive advantage. D) The play behavior performed by juveniles allows them to perfect adult behaviors that are needed for survival, such as hunting, courtship, and so on. E) The evolutionary "game" is played between predator and prey, wherein the prey develops a behavior through natural selection that enables it to be less vulnerable to predation, and the predator counters with a new reciprocal predatory behavior.
Answer: A
49 In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling? A) Growth factor ligands do not bind as efficiently to receptors. B) Their lower hormone concentrations elicit a lesser response. C) cAMP levels change very frequently. D) Enzymatic activity declines. E) ATP production decreases.
Answer: A
49 The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? A) The pH within the thylakoid is less than that of the stroma. B) The pH of the stroma is lower than that of the other two measurements. C) The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. D) The pH of the thylakoid space is higher than that anywhere else in the cell. E) There is no consistent relationship.
Answer: A
5 5) Which of the following choices includes all of the others in creating global terrestrial climates? A) differential heating of Earth's surface B) ocean currents C) global wind patterns D) evaporation of water from ocean surfaces E) Earth's rotation on its axis
Answer: A
5 Water molecules are able to form hydrogen bonds with A) compounds that have polar covalent bonds. B) oils. C) oxygen gas (O₂) molecules. D) chloride ions. E) any compound that is not soluble in water.
Answer: A
5 Which of the following statements describes the results of this reaction? C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + Energy A) C₆H₁₂O₆ is oxidized and O₂ is reduced. B) O₂ is oxidized and H₂O is reduced. C) CO₂ is reduced and O₂ is oxidized. D) C₆H₁₂O₆ is reduced and CO₂ is oxidized. E) O₂ is reduced and CO₂ is oxidized.
Answer: A
50 Familial hypercholesterolemia is characterized by which of the following? A) defective LDL receptors on the cell membranes B) poor attachment of the cholesterol to the extracellular matrix of cells C) a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes D) inhibition of the cholesterol active transport system in red blood cells E) a general lack of glycolipids in the blood cell membranes
Answer: A
50 Which of the following correctly describes chemical equilibrium? A) Forward and reverse reactions continue with no effect on the concentrations of the reactants and products. B) Concentrations of products are higher than the concentrations of the reactants. C) Forward and reverse reactions have stopped so that the concentration of the reactants equals the concentration of the products. D) Reactions stop only when all reactants have been converted to products. E) There are equal concentrations of reactants and products, and the reactions have stopped.
Answer: A
50 card image The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all. 50) Which climograph shows the climate for location 1? A) A B) C C) E D) G E) H
Answer: A
51 51) In a life cycle such as that shown in part III of Figure 13.1, if the zygote's chromosome number is 10, which of the following will be true? A) The sporophyte's chromosome number per cell is 10 and the gametophyte's is 5. B) The sporophyte's chromosome number per cell is 5 and the gametophyte's is 10. C) The sporophyte and gametophyte each have 10 chromosomes per cell. D) The sporophyte and gametophyte each have 5 chromosomes per cell. E) The sporophyte and gametophyte each have 20 chromosomes per cell.
Answer: A
51 Protein kinases are enzymes that catalyze phosphorylation of target proteins at specific sites, whereas protein phosphatases catalyze removal of phosphate(s) from phosphorylated proteins. Phosphorylation and dephosphorylation can function as an on-off switch for a protein's activity, most likely through A) the change in a protein's charge leading to a conformational change. B) the change in a protein's charge leading to cleavage. C) a change in the optimal pH at which a reaction will occur. D) a change in the optimal temperature at which a reaction will occur. E) the excision of one or more peptides.
Answer: A
52 Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. Which of the following hypotheses is most plausible in light of such structural similarities? A) Cilia and flagella arise from the centrioles. B) Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles. C) Motor proteins such as dynein must have evolved before any of these four kinds of structure. D) Cilia and flagella coevolved in the same ancestral eukaryotic organism. E) Natural selection for cell motility repeatedly selected for microtubular arrays in circular patterns in the evolution of each of these structures.
Answer: A
52 In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (¹⁴C) dioxide as a metabolic tracer. The ¹⁴C is incorporated first into oxaloacetate. The plant is best characterized as a A) C₄ plant. B) C₃ plant. C) CAM plant. D) heterotroph. E) chemoautotroph.
Answer: A
52 Which of these systems is least likely to be at chemical equilibrium? A) a test tube of living cells B) a test tube of organic molecules, kept in the freezer C) a test tube of dry organic molecules, kept at room temperature D) a test tube of organic molecules dissolved in water, kept at room temperature E) a test tube of dead cells in water, kept at room temperature
Answer: A
52 card image 52) Which curve best describes survivorship in elephants? A) A B) B C) C D) D E) E
Answer: A
52 card image Figure 13.2 of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis 52) Which diagram represents anaphase I of meiosis? A) I B) II C) IV D) V E) VI
Answer: A
52 card image Which molecule(s) shown above is (are) ionized in aqueous solution at pH 7? A) A B) B and D C) D and E D) D E) E
Answer: A
53 53) In a relaxed skeletal muscle, actin is not chemically bound to A) myosin. B) troponin. C) tropomyosin. D) Z lines
Answer: A
53 53) The biggest challenge that Costa Rica will likely face in its dedication to conservation and restoration in the future is A) the pressures of its growing population. B) its small size (as a country), which may not be able to maintain large enough reserves. C) the potential for disturbance of sensitive species in reserves by ecotourists. D) spread of disease and parasites via corridors from neighboring countries. E) the large number of Costa Rican species already in the extinction vortex.
Answer: A
53 card image Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely A) positively charged. B) negatively charged. C) without charge. D) hydrophobic. E) nonpolar
Answer: A
54 54) Which of the following nations has become a world leader in the establishment of zoned reserves? A) Costa Rica B) Canada C) China D) United States E) Mexico
Answer: A
54 CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they A) fix CO₂ into organic acids during the night. B) fix CO₂ into sugars in the bundle-sheath cells. C) fix CO₂ into pyruvate in the mesophyll cells. D) use the enzyme phosphofructokinase, which outcompetes rubisco for CO₂. E) use photosystem I and photosystem II at night.
Answer: A
54 card image 54) Which curve best describes survivorship in humans who live in undeveloped nations? A) A B) B C) C D) D E) E
Answer: A
54 card image You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in Figure 13.3. Refer to the graph to answer the following questions. 54) Which sample of DNA might be from a nerve cell arrested in G0 of the cell cycle? A) I B) II C) III D) either I or II E) either I or III
Answer: A
55 55) What is the first step in ecosystem restoration? A) to restore the physical structure B) to restore native species that have been extirpated due to disturbance C) to remove competitive invasive species D) to identify the limiting factors of the producers E) to remove toxic pollutants
Answer: A
55 card image 55) Based on what you know about ecosystem stability and the information provided in the graph, which community (A-E) would likely support the most biodiversity? A) A B) B C) C D) D E) E
Answer: A
56 Which of the following normally occurs regardless of whether or not oxygen (O₂) is present? A) glycolysis B) fermentation C) oxidation of pyruvate to acetyl CoA D) citric acid cycle E) oxidative phosphorylation (chemiosmosis)
Answer: A
56 card image 56) G₁ is represented by which numbered part(s) of the cycle? A) I or V B) II or IV C) III only D) IV only E) V only
Answer: A
56 card image You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in Figure 13.3. Refer to the graph to answer the following questions. 56) Which sample might represent a zygote? A) I B) II C) III D) either I or II E) either II or III
Answer: A
57 57) The lumen of the transverse tubules of skeletal muscles contains A) extracellular fluid. B) cytosol. C) actin. D) myosin. E) sarcomeres.
Answer: A
57 Which of the following is not an observation or inference on which Darwin's theory of natural selection is based? A) Poorly adapted individuals never produce offspring. B) There is heritable variation among individuals. C) Because of overproduction of offspring, there is competition for limited resources. D) Individuals whose inherited characteristics best fit them to the environment will generally produce more offspring. E) A population can become adapted to its environment over time.
Answer: A
57 Which of the following occurs in the cytosol of a eukaryotic cell? A) glycolysis and fermentation B) fermentation and chemiosmosis C) oxidation of pyruvate to acetyl CoA D) citric acid cycle E) oxidative phosphorylation
Answer: A
57 card image A small birthday candle is weighed, then lighted and placed beneath a metal can containing 100 mL of water. Careful records are kept as the temperature of the water rises. Data from this experiment are shown on the graph. What amount of heat energy is released in the burning of candle wax? A) 0.5 kilocalories per gram of wax burned B) 5 kilocalories per gram of wax burned C) 10 kilocalories per gram of wax burned D) 20 kilocalories per gram of wax burned E) 50 kilocalories per gram of wax burned
Answer: A
57 card image Use the following diagram of five islands formed at around the same time near a particular mainland, as well as MacArthur and Wilson's island biogeography principles, to answer the following question. Figure 54.4 57) Which island would likely have the lowest extinction rate? A) A B) B C) C D) D E) E
Answer: A
58 58) In a typical grassland community, which of the following has the smallest biomass? A) hawk B) snake C) shrew D) grasshopper E) grass
Answer: A
58 Compared to C₃ plants, C₄ plants A) can continue to fix CO₂ even at relatively low CO2 concentrations and high oxygen concentrations. B) have higher rates of photorespiration. C) do not use rubisco for carbon fixation. D) grow better under cool, moist conditions. E) make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria.
Answer: A
59 Humans have receptors for two kinds of beta adrenergic compounds such as catecholamines to control cardiac muscle contractions. Some are beta 1 receptors that promote increased heart rate. Other drugs, called beta blockers, slow heart rate. Smooth muscle cells, however, have beta 2 receptors, which mediate muscle relaxation. Blockers of these effects are sometimes used to treat asthma. The description above illustrates which of the following? A) Just because a drug acts on one type of receptor does not mean that it will act on another type. B) Beta blockers can be used effectively on any type of muscle. C) Beta adrenergic receptors must be in the cytosol if they are going to influence contraction and relaxation. D) The chemical structures of the beta 1 and beta 2 receptors must have the same active sites.
Answer: A
59 The next question presumes that you have at least once visited and have some knowledge of the fast-food restaurant McDonald's. Use your knowledge of McDonald's and your understanding of community ecology to answer the following questions about an ecological community, McDonaldland. 59) Which of the following would be considered a keystone species in McDonaldland? A) Big Mac B) Large French Fries C) Premium Caesar Salad with Crispy Chicken D) Filet-O-Fish E) Chicken McNuggets
Answer: A
59 card image 59) Which of the following is a likely graphic outcome of a population of deer introduced to an island with an adequate herbivory and without natural predators, parasites, or disease? A. SEE IMAGE B. SEE IMAGE C. SEE IMAGE D. SEE IMAGE E. SEE IMAGE
Answer: A
6 6) Tastes and smells are distinct kinds of environmental information in that A) neural projections from taste receptors reach different parts of the brain than the neural projections from olfactory receptors. B) the single area of the cerebral cortex that receives smell and taste signals can distinguish tastes and smells by the pattern of action potentials received. C) tastant molecules are airborne, whereas odorant molecules are dissolved in fluids. D) distinguishing tastant molecules requires learning, whereas smell discrimination is an innate process. E) odorants bind to receptor proteins, but none of the tastant stimuli bind to receptors.
Answer: A
6 6) What type of signal is long-lasting and works at night? A) olfactory B) visual C) auditory D) tactile E) electrical
Answer: A
6 6) Which of the following groups would be most likely to exhibit uniform dispersion? A) red squirrels, who actively defend territories B) cattails, which grow primarily at edges of lakes and streams C) dwarf mistletoes, which parasitize particular species of forest tree D) moths, in a city at night E) lake trout, which seek out cold, deep water high in dissolved oxygen
Answer: A
6 The presence of cholesterol in the plasma membranes of some animals A) enables the membrane to stay fluid more easily when cell temperature drops. B) enables the animal to remove hydrogen atoms from saturated phospholipids. C) enables the animal to add hydrogen atoms to unsaturated phospholipids. D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell. E) makes the animal more susceptible to circulatory disorders.
Answer: A
60 60) Suppose you attend a town meeting at which some experts tell the audience that they have performed a cost-benefit analysis of a proposed transit system that would probably reduce overall air pollution and fossil fuel consumption. The analysis, however, reveals that ticket prices will not cover the cost of operating the system when fuel, wages, and equipment are taken into account. As a biologist, you know that if ecosystem services had been included in the analysis the experts might have arrived at a different answer. Why are ecosystem services rarely included in economic analyses? A) Their cost is difficult to estimate and people take them for granted. B) They are not worth much and are usually not considered. C) There are no laws that require investigation of ecosystem services in environmental planning. D) There are too many variables to ecosystem services, making their calculation impossible. E) Ecosystem services only take into account abiotic factors that affect local environments.
Answer: A
60 In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of A) ATP, CO₂, and ethanol (ethyl alcohol). B) ATP, CO₂, and lactate. C) ATP, NADH, and pyruvate. D) ATP, pyruvate, and oxygen. E) ATP, pyruvate, and acetyl CoA.
Answer: A
60 card image The diagram shows a generalized cross section of the marine environment with various zones labeled with letters. Choose the letter that best answers the question. Letters may be used once, more than once, or not at all 60) Which zone experiences the most abiotic change over a 24-hour period? A) A B) B C) C D) D E) E
Answer: A
60 card image Which molecule shown above contains an amino functional group, but is not an amino acid? A) A B) B C) C D) D E) E
Answer: A
61 In alcohol fermentation, NAD⁺ is regenerated from NADH by A) reduction of acetaldehyde to ethanol (ethyl alcohol). B) oxidation of pyruvate to acetyl CoA. C) reduction of pyruvate to form lactate. D) oxidation of ethanol to acetyl CoA. E) reduction of ethanol to pyruvate.
Answer: A
61 card image Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species) 61) Examine this food web for a particular terrestrial ecosystem. Which species is autotrophic? A) A B) B C) C D) D E) E
Answer: A
61 card image Use the data in Table 12.1 to answer the following question. (SEE IMAGE) The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma 61) Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that A) gamma contains more DNA than beta. B) beta and gamma contain the same amount of DNA. C) beta cells reproduce asexually. D) gamma contains 48 times more DNA and RNA than beta. E) beta is a plant cell and gamma is an animal cell.
Answer: A
63 63) Fred and Joe, two unrelated, mature male gorillas, encounter one another. Fred is courting a female. Fred grunts as Joe comes near. As Joe continues to advance, Fred begins drumming (pounding his chest) and bares his teeth. Joe then rolls on the ground on his back, gets up, and quickly leaves. This behavioral pattern is repeated several times during the mating season. Choose the most specific behavior described by this example. A) agonistic behavior B) territorial behavior C) learned behavior D) social behavior E) fixed action pattern
Answer: A
63 63) How is natural selection related to sexual reproduction as opposed to asexual reproduction? A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction. B) Sexual reproduction results in the most appropriate and healthiest balance of two sexes in the population. C) Sexual reproduction results in the greatest number of new mutations. D) Sexual reproduction allows the greatest number of offspring to be produced. E) Sexual reproduction utilizes far less energy than asexual reproduction.
Answer: A
63 card image The following questions refer to Figure 53.3, which depicts the age structure of three populations. 63) Assuming these age-structure diagrams describe human populations, in which population is unemployment likely to be a societal issue in the future? A) I B) II C) III D) No differences in the magnitude of future unemployment would be expected among these populations. E) It is not possible to infer anything about future social conditions from age-structure diagrams.
Answer: A
63 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction, C + D → A + B, in Figure 8.1? A) a B) b C) c D) d E) e
Answer: A
63 card image Which molecule shown above can function as a base? A) A B) B C) C D) D E) E
Answer: A
64 64) A human cell containing 22 autosomes and a Y chromosome is A) a sperm. B) an egg. C) a zygote. D) a somatic cell of a male. E) a somatic cell of a female.
Answer: A
64 The activation of receptor tyrosine kinases is characterized by A) dimerization and phosphorylation. B) dimerization and IP3 binding. C) a phosphorylation cascade. D) GTP hydrolysis. E) channel protein shape change.
Answer: A
64 Which statement best supports the hypothesis that glycolysis is an ancient metabolic pathway that originated before the last universal common ancestor of life on Earth? A) Glycolysis is widespread and is found in the domains Bacteria, Archaea, and Eukarya. B) Glycolysis neither uses nor needs O₂. C) Glycolysis is found in all eukaryotic cells. D) The enzymes of glycolysis are found in the cytosol rather than in a membrane-enclosed organelle. E) Ancient prokaryotic cells, the most primitive of cells, made extensive use of glycolysis long before oxygen was present in Earth's atmosphere.
Answer: A
65 65) Which of the following is a consequence of biological magnification? A) Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers. B) Populations of top-level predators are generally smaller than populations of primary consumers. C) The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers. D) Only a small portion of the energy captured by producers is transferred to consumers. E) The amount of biomass in the producer level of an ecosystem decreases if the producer turnover time increases.
Answer: A
66 Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP. Identify the second messenger. A) cAMP B) G protein C) GTP D) adenylyl cyclase E) G protein-coupled receptor
Answer: A
66 Recent evidence shows that signals from the extracellular matrix (ECM) can regulate the expression of genes in the cell nucleus. A likely mechanism is that A) mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signaling. B) intracellular signals might cause changes in the fibronectin binding to the cell surface. C) orientation of microtubules to the ECM can change gene activity. D) integrins that receive signals from the ECM migrate to the nucleus. E) proteoglycans in the ECM undergo endocytosis and produce intracellular signaling molecules.
Answer: A
66 card image Diagram of a food web (arrows represent energy flow and letters represent species) 66) If the figure above represents a marine food web, the smallest organism might be A) A. B) F. C) C. D) I. E) E.
Answer: A
66 card image The illustration above shows a representation of formic acid. A formic acid molecule A) will form hydrogen bonds with water molecules. B) has a tetrahedral configuration of hybrid electron orbitals for the carbon atom. C) consists of largely nonpolar covalent bonds. D) is held together by hydrogen bonds. E) has a tetrahedral shape and will form hydrogen bonds with water molecules.
Answer: A
67 67) Meiosis II is similar to mitosis in that A) sister chromatids separate during anaphase. B) DNA replicates before the division. C) the daughter cells are diploid. D) homologous chromosomes synapse. E) the chromosome number is reduced.
Answer: A
67 67) Of the following statements about protected areas that have been established to preserve biodiversity, which one is not correct? A) About 25% of Earth's land area is now protected. B) National parks are one of many types of protected areas. C) Most protected areas are too small to protect species. D) Management of a protected area should be coordinated with management of the land surrounding the area. E) It is especially important to protect biodiversity hot spots.
Answer: A
67 card image Which of the following statements is true concerning Figure 10.3? A) It represents cell processes involved in C₄ photosynthesis. B) It represents the type of cell structures found in CAM plants. C) It represents an adaptation that maximizes photorespiration. D) It represents a C₃ photosynthetic system. E) It represents a relationship between plant cells that photosynthesize and those that cannot.
Answer: A
68 68) Your friend comes to you with a problem. It seems his shrimp boats aren't catching nearly as much shrimp as they used to. He can't understand why because he used to catch all the shrimp he could handle. Each year he added a new boat, and for a long time each boat caught tons of shrimp. As he added more boats, there came a time when each boat caught somewhat fewer shrimp, and now, each boat is catching a lot less shrimp. Which of the following topics might help your friend understand the source of his problem? A) density-dependent population regulation and intrinsic characteristics of population growth B) exponential growth curves and unlimited environmental resources C) density-independent population regulation and chance occurrence D) pollution effects of a natural environment and learned shrimp behavior E) a K-selected population switching to an r-selected population
Answer: A
68 Measurements show that the pH of a particular lake is 4.0. What is the hydroxide ion concentration of the lake? A) 10⁻¹⁰ M B) 10⁻⁴ M C) 10⁻⁷ M D) 10⁻¹⁴ M E) 10 M
Answer: A
69 69) Which of the following is not required for a behavioral trait to evolve by natural selection? A) In each individual, the form of the behavior is determined entirely by genes. B) The behavior varies among individuals. C) An individual's reproductive success depends in part on how the behavior is performed. D) Some component of the behavior is genetically inherited. E) An individual's genotype influences its behavioral phenotype.
Answer: A
69 A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells? A) The mutant yeast will be unable to grow anaerobically. B) The mutant yeast will grow anaerobically only when given glucose. C) The mutant yeast will be unable to metabolize glucose. D) The mutant yeast will die because they cannot regenerate NAD⁺ from NAD. E) The mutant yeast will metabolize only fatty acids.
Answer: A
69 card image 69) On the diagram of the nitrogen cycle, which number represents nitrogen-fixing bacteria? A) 5 B) 6 C) 7
Answer: A
69 card image Choose the term that correctly describes the relationship between these two sugar molecules: A) structural isomers B) cis-trans isomers C) enantiomers D) isotopes
Answer: A
4 4) During the spring, you are studying the mice that live in a field near your home. The population density is high, but you realize that you rarely observe any reproductive female mice. This most likely indicates A) that there is selective predation on female mice. B) that female mice die before reproducing. C) that this habitat is a good place for mice to reproduce. D) that you are observing immigrant mice. E) that the breeding season is over.
Answer: D
7 According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids? A) They can move laterally along the plane of the membrane. B) They frequently flip-flop from one side of the membrane to the other. C) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. D) They are free to depart from the membrane and dissolve in the surrounding solution. E) They have hydrophilic tails in the interior of the membrane.
Answer: A
70 A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. 70) When a cell is in anaphase of mitosis, which of the following will he see? A) a clear area in the center of the cell B) chromosomes clustered at the poles C) individual chromatids separating D) chromosomes clustered tightly at the center E) formation of vesicles at the midline
Answer: A
70 You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body? A) It was released as CO₂ and H₂O. B) It was converted to heat and then released. C) It was converted to ATP, which weighs much less than fat. D) It was broken down to amino acids and eliminated from the body. E) It was converted to urine and eliminated from the body.
Answer: A
70 card image How do cells use the ATP cycle shown in the figure? A) Cells use the cycle to recycle ADP and phosphate. B) Cells use the cycle to recycle energy released by ATP hydrolysis. C) Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis. D) Cells use the cycle to generate or consume water molecules as needed. E) Cells use the cycle primarily to generate heat.
Answer: A
71 71) A population's carrying capacity A) may change as environmental conditions change. B) can be accurately calculated using the logistic growth model. C) generally remains constant over time. D) increases as the per capita growth rate (r) decreases. E) can never be exceeded.
Answer: A
71 71) When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes A) in biomes at different latitudes. B) at different depths in the ocean. C) in a community through different seasons. D) in an ecosystem as it evolves over time. E) across the United States from east to west.
Answer: A
71 card image Which action could produce a carbonyl group? A) the replacement of the OH of a carboxyl group with hydrogen B) the addition of a thiol to a hydroxyl C) the addition of a hydroxyl to a phosphate D) the replacement of the nitrogen of an amine with oxygen E) the addition of a sulfhydryl to a carboxyl
Answer: A
72 Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount of ATP in a cell would be expected to A) inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle. B) activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle. C) inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle. D) activate the enzyme and increase the rates of glycolysis and the citric acid cycle. E) inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate.
Answer: A
72 Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. What is malonic acid's role with respect to succinate dehydrogenase? A) It is a competitive inhibitor. B) It blocks the binding of fumarate. C) It is a noncompetitive inhibitor. D) It is able to bind to succinate. E) It is an allosteric regulator.
Answer: A
73 73) According to the equilibrium model of island biogeography, species richness would be greatest on an island that is A) large and close to a mainland. B) large and remote. C) small and remote. D) small and close to a mainland. E) environmentally homogeneous.
Answer: A
73 73) Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to A) disruption of mitotic spindle formation. B) inhibition of regulatory protein phosphorylation. C) suppression of cyclin production. D) myosin denaturation and inhibition of cleavage furrow formation. E) inhibition of DNA synthesis.
Answer: A
73 card image If two molecules of the general type shown in Figure 5.1 were linked together, carbon-1 of one molecule to carbon-4 of the other, the single molecule that would result would be A) maltose. B) fructose. C) glucose. D) galactose. E) sucrose.
Answer: A
74 A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. If the power fails and the lights go dark, what will happen to CO₂ levels? A) CO₂ will rise as a result of both animal and plant respiration. B) CO₂ will rise as a result of animal respiration only. C) CO₂ will remain balanced because plants will continue to fix CO₂ in the dark. D) CO₂ will fall because plants will increase CO₂ fixation. E) CO₂ will fall because plants will cease to respire in the dark.
Answer: A
76 76) In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A) cells with more than one nucleus. B) cells that are unusually small. C) cells lacking nuclei. D) destruction of chromosomes. E) cell cycles lacking an S phase.
Answer: A
76 In the term trace element, the modifier trace means that A) the element is required in very small amounts. B) the element can be used as a label to trace atoms through an organism's metabolism. C) the element is very rare on Earth. D) the element enhances health but is not essential for the organism's long-term survival. E) the element passes rapidly through the organism.
Answer: A
77 What carbon sources can yeast cells metabolize to make ATP from ADP under anaerobic conditions? A) glucose B) ethanol C) pyruvate D) lactic acid E) either ethanol or lactic acid
Answer: A
78 78) A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in A) G₁. B) G₂. C) prophase. D) metaphase. E) anaphase.
Answer: A
78 78) The middle ear converts A) air pressure waves to fluid pressure waves. B) fluid pressure waves to air pressure waves. C) air pressure waves to nerve impulses. D) fluid pressure waves to nerve impulses. E) pressure waves to hair cell movements.
Answer: A
78 Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the A) mitochondria. B) ribosomes. C) peroxisomes. D) lysosomes. E) endoplasmic reticulum.
Answer: A
78 If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to A) add more of the enzyme. B) heat the solution to 90°C. C) add more substrate. D) add an allosteric inhibitor. E) add a noncompetitive inhibitor.
Answer: A
78 Which of the following factors would tend to increase membrane fluidity? A) a greater proportion of unsaturated phospholipids B) a greater proportion of saturated phospholipids C) a lower temperature D) a relatively high protein content in the membrane E) a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses
Answer: A
8 8) According to the U.S. Endangered Species Act (ESA), the difference between an endangered species and a threatened one is that A) an endangered species is closer to extinction. B) a threatened species is closer to extinction. C) threatened species are endangered species outside the U.S. borders. D) endangered species are mainly tropical. E) only endangered species are vertebrates.
Answer: A
8 8) Which of the following terms encompasses all of the others? A) heterotrophs B) herbivores C) carnivores D) primary consumers E) secondary consumers
Answer: A
8 In an experiment to track the movement of growth factor molecules from secretion to the point of receptor binding in a particular species of mammal, a student found a 20-fold reduction in mm traveled when in the presence of an adrenal hormone. This is in part attributable to which of the following? A) The growth factor is a paracrine signal. B) The growth factor depends on osmosis. C) The mammal only carries growth factor through the lymph. D) The growth factor is an exocrine signal. E) The growth factor is an endocrine signal.
Answer: A
8 What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division? A) light microscopy B) scanning electron microscopy C) transmission electron microscopy D) confocal fluorescence microscopy E) super-resolution fluorescence microscopy
Answer: A
8 Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? A) by increasing the percentage of unsaturated phospholipids in the membrane B) by increasing the percentage of cholesterol molecules in the membrane C) by decreasing the number of hydrophobic proteins in the membrane D) by cotransport of glucose and hydrogen E) by using active transport
Answer: A
8 Which of the following statements describes NAD⁺? A) NAD⁺ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. B) NAD⁺ has more chemical energy than NADH. C) NAD⁺ is oxidized by the action of hydrogenases. D) NAD⁺ can donate electrons for use in oxidative phosphorylation. E) In the absence of NAD⁺, glycolysis can still function.
Answer: A
80 80) Which of the following would be considered an example of bioremediation? A) adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability B) using a bulldozer to regrade a strip mine C) dredging a river bottom to remove contaminated sediments D) reconfiguring the channel of a river E) adding seeds of a chromium-accumulating plant to soil contaminated by chromium
Answer: A
80 Yeast cells that have defective mitochondria incapable of respiration will be able to grow by catabolizing which of the following carbon sources for energy? A) glucose B) proteins C) fatty acids D) glucose, proteins, and fatty acids E) Such yeast cells will not be capable of catabolizing any food molecules, and will therefore die.
Answer: A
82 card image Which bond is closest to the amino terminus of the molecule? A) A B) B C) C D) D E) E
Answer: A
84 card image Which portion of the pathway in Figure 9.1 involves an endergonic reaction? A) A B) B C) C D) D E) E
Answer: A
85 card image Which portion of the pathway in Figure 9.1 contains a phosphorylation reaction in which ATP is the phosphate source? A) A B) B C) C D) D E) E
Answer: A
86 card image Starting with one molecule of isocitrate and ending with fumarate, how many ATP molecules can be made through substrate-level phosphorylation (see Figure 9.2)? A) 1 B) 2 C) 11 D) 12 E) 24
Answer: A
9 9) Immediately after putting on a shirt, your skin might feel itchy. However, this perception soon fades due to A) sensory adaptation. B) accommodation. C) the increase of transduction. D) reduced motor unit recruitment. E) reduced receptor amplification.
Answer: A
9 9) Which of the following is an example of aposematic coloration? A) stripes of a skunk B) eye color in humans C) green color of a plant D) colors of an insect-pollinated flower E) a katydid whose wings look like a dead leaf
Answer: A
97 [SEE IMAGE FOR CARD #84] Which of the following molecules has a functional group that frequently forms covalent bonds that maintain the tertiary structure of a protein? A) 2 B) 3 C) 7 D) 8 E) 9
Answer: A
98 Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated further, however, the ability to synthesize ATP is lost. After the first disruption, when electron transfer and ATP synthesis still occur, what must be present? A) all of the electron transport proteins as well as ATP synthase B) all of the electron transport system and the ability to add CoA to acetyl groups C) the ATP synthase system D) the electron transport system E) plasma membranes like those bacteria use for respiration
Answer: A
Using the yeast signal transduction pathways, both types of mating cells release the mating factors. These factors bind to specific receptors on the correct cells, A) which induce changes in the cells that lead to cell fusion. B) which produce more of the a factor in a positive feedback. C) then one cell nucleus binds the mating factors and produces a new nucleus in the opposite cell. D) stimulating cell membrane disintegration, releasing the mating factors that lead to new yeast cells. E) which in turn releases a growth factor that stimulates mitosis in both cells.
Answer: A
bacteria do not. C) DNA is present in both archaea cells and bacteria cells. D) DNA is present in the mitochondria of both bacteria and archaea cells.
Answer: A
each hydrogen atom has a slight negative charge. E) There are covalent bonds between the hydrogen atoms and polar bonds between each hydrogen atom and the nitrogen atom.
Answer: A
therefore, the species is photosynthetic. B) These organisms live in sunny parts of this area so they are able to photosynthesize. C) If horses are always found grazing on grass, they can be only herbivores and not omnivores. D) If protists are all single-celled, then they are incapable of aggregating. E) If two species are members of the same genus, they are more alike than each of them could be to a different genus.
Answer: A
1) Population ecologists are primarily interested in A) studying interactions among populations of organisms that inhabit the same area. B) understanding how biotic and abiotic factors influence the density, distribution, size, and age structure of populations. C) how humans affect the size of wild populations of organisms. D) how populations evolve as natural selection acts on heritable variations among individuals and changes in gene frequency. E) the overall vitality of a population of organisms.
Answer: B
1) The 11 pairs of appendages projecting from the rostral area of star-nosed moles are A) chemosensory structures. B) tactile structures. C) olfactory structures. D) highly sensitive photoreceptors. E) gustatory structures.
Answer: B
10 10) Research has shown that nocturnal animals navigate using A) olfactory cues. B) the North Star. C) the moon. D) landmarks. E) gravity.
Answer: B
10 In the thylakoid membranes, what is the main role of the antenna pigment molecules? A) split water and release oxygen to the reaction-center chlorophyll B) harvest photons and transfer light energy to the reaction-center chlorophyll C) synthesize ATP from ADP and Pi D) transfer electrons to ferredoxin and then NADPH E) concentrate photons within the stroma
Answer: B
107 Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A) The two strands of the double helix would separate. B) The phosphodiester linkages of the polynucleotide backbone would be broken. C) The purines would be separated from the deoxyribose sugars. D) The pyrimidines would be separated from the deoxyribose sugars. E) All bases would be separated from the deoxyribose sugars.
Answer: B
107 Most CO₂ from catabolism is released during A) glycolysis. B) the citric acid cycle. C) lactate fermentation. D) electron transport. E) oxidative phosphorylation.
Answer: B
11 11) Referring to a plant's sexual life cycle, which of the following terms describes the process that leads directly to the formation of gametes? A) sporophyte meiosis B) gametophyte mitosis C) gametophyte meiosis D) sporophyte mitosis E) alternation of generations
Answer: B
11 11) Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? A) kinetochores B) Golgi-derived vesicles C) actin and myosin D) centrioles and centromeres E) cyclin-dependent kinases
Answer: B
11 The oxygen consumed during cellular respiration is involved directly in which process or event? A) glycolysis B) accepting electrons at the end of the electron transport chain C) the citric acid cycle D) the oxidation of pyruvate to acetyl CoA E) the phosphorylation of ADP to form ATP
Answer: B
12 12) Upon returning to its hive, a European honeybee communicates to other worker bees the location of a nearby food source it has discovered by A) vibrating its wings at varying frequencies. B) performing a round dance. C) performing a waggle dance. D) visual cues. E) All options are correct.
Answer: B
12 12) Which of the following is an example of alternation of generations? A) A grandparent and grandchild each have dark hair, but the parent has blond hair. B) A diploid plant (sporophyte) produces, by meiosis, a spore that gives rise to a multicellular, haploid pollen grain (gametophyte). C) A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote. D) A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis. E) A diploid cell divides by mitosis to produce two diploid daughter cells, which then fuse to produce a tetraploid cell.
Answer: B
12 12) Which of the following scenarios would provide the most legitimate data on population density? A) Count the number of nests of a particular species of songbird and multiply this by a factor that extrapolates these data to actual animals. B) Count the number of pine trees in several randomly selected 10 m x 10 m plots and extrapolate this number to the fraction of the study area these plots represent. C) Use the mark-and-recapture method to estimate the size of the population. D) Calculate the difference between all of the immigrants and emigrants to see if the population is growing or shrinking. E) Add the number of births and subtract the individuals that die to see if the population's density is increasing or decreasing.
Answer: B
12 Testosterone functions inside a cell by A) acting as a signal receptor that activates tyrosine kinases. B) binding with a receptor protein that enters the nucleus and activates specific genes. C) acting as a steroid signal receptor that activates ion channel proteins. D) becoming a second messenger that inhibits adenylyl cyclase. E) coordinating a phosphorylation cascade that increases spermatogenesis.
Answer: B
12 Which process in eukaryotic cells will proceed normally whether oxygen (O₂) is present or absent? A) electron transport B) glycolysis C) the citric acid cycle D) oxidative phosphorylation E) chemiosmosis
Answer: B
13 13) Karl von Frisch demonstrated that European honeybees communicate the location of a distant food source by A) performing a short, straight run during a waggle dance. B) performing a long, straight run during a waggle dance. C) performing a round dance with fast rotations. D) emanating minute amounts of stimulus pheromone. E) varying wing vibration frequency.
Answer: B
13 13) The major role of detrivores in ecosystems is to A) provide a nutritional resource for heterotrophs. B) recycle chemical nutrients to a form capable of being used by autotrophs. C) prevent the buildup of the organic remains of organisms, feces, and so on. D) return energy lost to the ecosystem by other organisms.
Answer: B
13 13) The most serious consequence of a decrease in global biodiversity would be the A) increase in global warming and thinning of the ozone layer. B) potential loss of ecosystem services on which people depend. C) increase in the abundance and diversity of edge-adapted species. D) loss of source of genetic diversity to preserve endangered species. E) loss of species for "bioprospecting."
Answer: B
13 An electron loses potential energy when it A) shifts to a less electronegative atom. B) shifts to a more electronegative atom. C) increases its kinetic energy. D) increases its activity as an oxidizing agent. E) moves further away from the nucleus of the atom.
Answer: B
13 Which of the following are directly associated with photosystem I? A) harvesting of light energy by ATP B) receiving electrons from the thylakoid membrane electron transport chain C) generation of molecular oxygen D) extraction of hydrogen electrons from the splitting of water E) passing electrons to the thylakoid membrane electron transport chain
Answer: B
13 Why does evaporation of water from a surface cause cooling of the surface? A) The breaking of bonds between water molecules absorbs heat. B) The water molecules with the most heat energy evaporate more readily. C) The solute molecules left behind absorb heat. D) Water molecules absorb heat from the surface in order to acquire enough energy to evaporate. E) The expansion of water vapor extracts heat from the surface.
Answer: B
4 4) Which of the following might be an investigation of microclimate? A) the effect of ambient temperature on the onset of caribou migration B) the seasonal population fluctuation of nurse sharks in coral reef communities C) competitive interactions between various species of songbirds during spring migration D) the effect of sunlight intensity on species composition in a decaying rat carcass E) the effect of different nitrogen applications on corn productivity
Answer: D
14 14) Approximately 1% of the solar radiation that strikes a plant is converted into the chemical bond energy of sugars. Why is this amount so low? A) Approximately 99% of the solar radiation is converted to heat energy. B) Only 1% of the wavelengths of visible light are absorbed by photosynthetic pigments. C) Most solar energy strikes water and land surfaces. D) Approximately 99% of the solar radiation is reflected. E) Only the green wavelengths are absorbed by plants for photosynthesis.
Answer: B
14 14) White-breasted nuthatches and Downy woodpeckers both eat insects that hide in the furrows of bark in hardwood trees. The Downy woodpecker searches for insects by hunting from the bottom of the tree trunk to the top, whereas the white-breasted nuthatch searches from the top of the trunk down. These hunting behaviors best illustrate which of the following ecological concepts? A) competitive exclusion B) resource partitioning C) character displacement D) keystone species E) bottom-up and top-down hypotheses
Answer: B
14 Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be A) to determine if they have thylakoids in the chloroplasts. B) to test for liberation of O₂ in the light. C) to test for CO₂ fixation in the dark. D) to do experiments to generate an action spectrum. E) to test for production of either sucrose or starch.
Answer: B
14 Which of these provides evidence of the common ancestry of all life? A) ubiquitous use of catalysts by living systems B) near universality of the genetic code C) structure of the nucleus D) structure of cilia E) structure of chloroplasts
Answer: B
14 Why are hydrocarbons insoluble in water? A) The majority of their bonds are polar covalent carbon-to-hydrogen linkages. B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. C) They are hydrophilic. D) They exhibit considerable molecular complexity and diversity. E) They are lighter than water.
Answer: B
15 15) Sound waves arriving at a listener first strike the A) tectorial membrane. B) tympanic membrane. C) round-window membrane. D) hair cell membrane. E) basilar membrane.
Answer: B
15 15) The main reason polar regions are cooler than the equator is that A) there is more ice at the poles. B) sunlight strikes the poles at a lower angle. C) the poles are farther from the sun. D) the polar atmosphere is thinner and contains fewer greenhouse gases. E) the poles are permanently tilted away from the sun.
Answer: B
15 Prokaryotes are classified as belonging to two different domains. What are the domains? A) Bacteria and Eukarya B) Bacteria and Archaea C) Archaea and Protista D) Bacteria and Protista E) Bacteria and Fungi
Answer: B
17 17) Which of the following best describes a karyotype? A) a pictorial representation of all the genes for a species B) a display of each of the chromosomes of a single cell C) the combination of all the maternal and paternal chromosomes of a species D) the collection of all the chromosomes in an individual organism E) a photograph of all the cells with missing or extra chromosomes
Answer: B
17 17) Why do chromosomes coil during mitosis? A) to increase their potential energy B) to allow the chromosomes to move without becoming entangled and breaking C) to allow the chromosomes to fit within the nuclear envelope D) to allow the sister chromatids to remain attached E) to provide for the structure of the centromere
Answer: B
17 Which of these individuals is likely to be most successful in an evolutionary sense? A) a reproductively sterile individual who never falls ill B) an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce C) a male who mates with 20 females and fathers one offspring D) an organism that lives 100 years and leaves two offspring, both of whom survive to reproduce E) a female who mates with 20 males and produces one offspring that lives to reproduce
Answer: B
18 18) A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost from) a population of 1,000 individuals in one year. A) 120 individuals added B) 40 individuals added C) 20 individuals added D) 400 individuals added E) 20 individuals lost
Answer: B
18 18) Dizziness is a perceived sensation that can occur when A) the hair cells in the cochlea move more than their normal limits. B) moving fluid in the semicircular canals encounters a stationary cupula. C) rods and cones provide information that does not correspond with information received by cochlear hair cells. D) the basilar membrane makes physical contact with the tectorial membrane. E) the utricle is horizontal but the saccule is vertical.
Answer: B
18 18) Overexploitation encourages extinction and is most likely to affect A) animals that occupy a broad ecological niche. B) large animals with low intrinsic reproductive rates. C) most organisms that live in the oceans. D) terrestrial organisms more than aquatic organisms. E) edge-adapted species.
Answer: B
18 In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population before they reproduce. Based on your knowledge of natural selection, you would predict that the average height of the human population will A) remain unchanged. B) gradually decline. C) rapidly decline. D) gradually increase. E) rapidly increase.
Answer: B
18 What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration? A) the presence or absence of bonds with oxygen atoms B) the presence or absence of double bonds between the carbon atom and other atoms C) the polarity of the covalent bonds between carbon and other atoms D) the presence or absence of bonds with nitrogen atoms E) the solvent that the organic molecule is dissolved in
Answer: B
19 Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms, but with one or more double bonds, will A) be more flexible in structure. B) be more constrained in structure. C) be more polar. D) have more hydrogen atoms. E) have fewer structurally distinct isomers.
Answer: B
19 When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: A) +ΔG, +ΔH, +ΔS. B) +ΔG, +ΔH, -ΔS. C) +ΔG, -ΔH, -ΔS. D) -ΔG, +ΔH, +ΔS. E) -ΔG, -ΔH, -ΔS.
Answer: B
2 2) According to the competitive exclusion principle, two species cannot continue to occupy the same A) habitat. B) niche. C) territory. D) range. E) biome.
Answer: B
2 2) The correct sequence of sensory processing is A) sensory adaptation → stimulus reception → sensory transduction → sensory perception. B) stimulus reception → sensory transduction → sensory perception → sensory adaptation. C) sensory perception → stimulus reception → sensory transduction → sensory adaptation. D) sensory perception → sensory transduction → stimulus reception → sensory adaptation. E) stimulus reception → sensory perception → sensory adaptation → sensory transduction.
Answer: B
2 2) Which of the following levels of ecological organization is arranged in the correct sequence from most to least inclusive? A) community, ecosystem, individual, population B) ecosystem, community, population, individual C) population, ecosystem, individual, community D) individual, population, community, ecosystem E) individual, community, population, ecosystem
Answer: B
2 Some regions of the plasma membrane, called lipid rafts, have a higher concentration of cholesterol molecules. As a result, these lipid rafts A) are more fluid than the surrounding membrane. B) are more rigid than the surrounding membrane. C) are able to flip from inside to outside. D) detach from the plasma membrane and clog arteries. E) have higher rates of lateral diffusion of lipids and proteins into and out of the lipid rafts.
Answer: B
40 40) Which trophic level is most vulnerable to extinction? A) producer level B) primary consumer level C) secondary consumer level D) tertiary consumer level E) decomposer level
Answer: D
20 20) A cage containing male mosquitoes has a small earphone placed on top, through which the sound of a female mosquito is played. All the males immediately fly to the earphone and go through all of the steps of copulation. What is the best explanation for this behavior? A) The males learn to associate the sound with females. B) Copulation is a fixed action pattern, and the female flight sound is a sign stimulus that initiates it. C) The sound from the earphone irritates the male mosquitoes, causing them to attempt to sting it. D) The reproductive drive is so strong that when males are deprived of females, they will attempt to mate with anything that has even the slightest female characteristic. E) Through classical conditioning, the male mosquitoes have associated the inappropriate stimulus from the earphone with the normal response of copulation.
Answer: B
40 At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects? A) Estrogen is produced in very large concentration and therefore diffuses widely. B) Estrogen has specific receptors inside several cell types, but each cell responds in the same way to its binding. C) Estrogen is kept away from the surface of any cells not able to bind it at the surface. D) Estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding. E) The subcomponents of estrogen, when metabolized, can influence cell response.
Answer: D
20 20) Air masses formed over the Pacific Ocean are moved by prevailing westerlies where they encounter extensive north-south mountain ranges, such as the Sierra Nevada and the Cascades. Which statement best describes the outcome of this encounter between a landform and an air mass? A) The cool, moist Pacific air heats up as it rises, releasing its precipitation as it passes the tops of the mountains, and this warm, now dry air cools as it descends on the leeward side of the range. B) The warm, moist Pacific air rises and cools, releasing precipitation as it moves up the windward side of the range, and this cool, now dry air mass heats up as it descends on the leeward side of the range. C) The cool, dry Pacific air heats up and picks up moisture from evaporation of the snowcapped peaks of the mountain range, releasing this moisture as precipitation when the air cools while descending on the leeward side of the range. D) These air masses are blocked by the mountain ranges, producing high annual amounts of precipitation on the windward sides of these mountain ranges. E) These air masses remain essentially unchanged in moisture content and temperature as they pass over these mountain ranges.
Answer: B
20 In glycolysis, for each molecule of glucose oxidized to pyruvate A) two molecules of ATP are used and two molecules of ATP are produced. B) two molecules of ATP are used and four molecules of ATP are produced. C) four molecules of ATP are used and two molecules of ATP are produced. D) two molecules of ATP are used and six molecules of ATP are produced. E) six molecules of ATP are used and six molecules of ATP are produced.
Answer: B
20 The formulation of a model for a structure or for a process serves which of the following purposes? A) It asks a scientific question. B) It functions as a testable hypothesis. C) It records observations. D) It serves as a data point among results. E) It can only be arrived at after years of experimentation.
Answer: B
20 What is the major difference between a kingdom and a domain? A) A kingdom can include several subgroups known as domains. B) All eukarya belong to one domain. C) All prokaryotes belong to one domain. D) The importance of fungi has led scientists to make them the whole of one domain. E) Only organisms that produce their own food belong to one of the domains.
Answer: B
40 One of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO₃⁻) and a hydrogen ion (H⁺). Thus, H₂CO₃ ↔ HCO₃⁻ + H⁺ If the pH of the blood drops, one would expect A) a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻. B) the concentration of hydroxide ion (OH⁻) to increase. C) the concentration of bicarbonate ion (HCO₃⁻) to increase. D) the HCO₃⁻ to act as a base and remove excess H⁺ with the formation of H₂CO₃. E) the HCO₃⁻ to act as an acid and remove excess H⁺ with the formation of H₂CO₃.
Answer: D
21 21) If global warming continues at its present rate, which biomes will likely take the place of the coniferous forest (taiga)? A) tundra and polar ice B) temperate broadleaf forest and grassland C) desert and chaparral D) tropical forest and savanna E) chaparral and temperate broadleaf forest
Answer: B
21 21) The total biomass of photosynthetic autotrophs present in an ecosystem is known as A) gross primary productivity. B) standing crop. C) net primary productivity. D) secondary productivity. E) trophic efficiency.
Answer: B
40 One of the key innovations in the evolution of eukaryotes from a prokaryotic ancestor is the endomembrane system. What eukaryotic organelles or features might have evolved as a part of, or as an elaboration of, the endomembrane system? A) plasma membrane B) chloroplasts C) mitochondria D) nuclear envelope E) none of these
Answer: D
21 A cell with a predominance of free ribosomes is most likely A) producing primarily proteins for secretion. B) producing primarily cytoplasmic proteins. C) constructing an extensive cell wall or extracellular matrix. D) digesting large food particles. E) enlarging its vacuole.
Answer: B
21 A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound? A) It lacks an asymmetric carbon, and it is probably a fat or lipid. B) It should dissolve in water. C) It should dissolve in a nonpolar solvent. D) It won't form hydrogen bonds with water. E) It is hydrophobic.
Answer: B
21 Which of the following best describes enthalpy (H)? A) the total kinetic energy of a system B) the heat content of a chemical system C) the system's entropy D) the cell's energy equilibrium E) the condition of a cell that is not able to react
Answer: B
40 The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation in eukaryotic cells is A) oxidation of glucose to CO₂ and water. B) the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers. C) the final transfer of electrons to oxygen. D) the proton-motive force across the inner mitochondrial membrane. E) the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP.
Answer: D
22 Which of the following statements best describes the relationship between photosynthesis and respiration? A) Respiration runs the biochemical pathways of photosynthesis in reverse. B) Photosynthesis stores energy in complex organic molecules, whereas respiration releases it. C) Photosynthesis occurs only in plants and respiration occurs only in animals. D) ATP molecules are produced in photosynthesis and used up in respiration. E) Respiration is anabolic and photosynthesis is catabolic.
Answer: B
23 23) A type of learning that can occur only during a brief period of early life and results in a behavior that is difficult to modify through later experiences is called A) insight. B) imprinting. C) habituation. D) operant conditioning. E) trial-and-error learning.
Answer: B
23 23) The energetic hypothesis and dynamic stability hypothesis are ideas that attempt to explain A) plant defenses against herbivores. B) the length of food chains. C) the evolution of mutualism. D) resource partitioning. E) competitive exclusion.
Answer: B
23 23) The generation of action potentials in olfactory neurons initiated by odors drawn in the nasal cavity is an example of A) perception. B) sensory transduction. C) sensory adaptation. D) habituation. E) lateral inhibition.
Answer: B
23 The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil? A) The hydrogenated vegetable oil has a lower melting point. B) The hydrogenated vegetable oil stays solid at room temperature. C) The hydrogenated vegetable oil has more "kinks" in the fatty acid chains. D) The hydrogenated vegetable oil has fewer trans fatty acids. E) The hydrogenated vegetable oil is less likely to clog arteries.
Answer: B
40 Which of the following is true of enzymes? A) Nonprotein cofactors alter the substrate specificity of enzymes. B) Enzyme function is increased if the 3-D structure or conformation of an enzyme is altered. C) Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. D) Enzymes increase the rate of chemical reaction by lowering activation energy barriers. E) Enzymes increase the rate of chemical reaction by providing activation energy to the substrate.
Answer: D
41 Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n) A) competitive inhibitor of the enzyme. B) noncompetitive inhibitor of the enzyme. C) allosteric activator of the enzyme. D) cofactor necessary for enzyme activity. E) coenzyme derived from a vitamin.
Answer: D
41 card image Which of the structures illustrated above contain(s) a carbonyl functional group? A) A B) C and D C) C D) D E) C and E
Answer: D
42 42) The olfactory bulbs are located A) in the nasal cavity. B) in the anterior pituitary gland. C) in the posterior pituitary gland. D) in the brain. E) in the brainstem.
Answer: D
42 42) Which statement best describes what ultimately happens to the chemical energy that is not converted to new biomass in the process of energy transfer between trophic levels in an ecosystem? A) It is undigested and winds up in the feces and is not passed on to higher trophic levels. B) It is used by organisms to maintain their life processes through the reactions of cellular respiration. C) Heat produced by cellular respiration is used by heterotrophs to thermoregulate. D) It is eliminated as feces or is dissipated into space as heat in accordance with the second law of thermodynamics. E) It is recycled by decomposers to a form that is once again usable by primary producers.
Answer: D
23 Why is ATP an important molecule in metabolism? A) Its hydrolysis provides an input of free energy for exergonic reactions. B) It provides energy coupling between exergonic and endergonic reactions. C) Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy. D) Its terminal phosphate bond has higher energy than the other two. E) It is one of the four building blocks for DNA synthesis.
Answer: B
24 24) In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely a(n) A) pathogen. B) keystone species. C) herbivore. D) resource partitioner. E) mutualistic organism.
Answer: B
24 24) Tastes and smells are similar in that A) both types of stimuli are present in thousands of different chemicals. B) both types of stimuli must be dissolved in a body fluid before they can be detected. C) both types of stimuli are proteins (that is, molecules of very large size and high molecular weight). D) both types of stimuli evoke action potentials in the cells to which they bind. E) any given stimulus for one system evokes a response from the other system.
Answer: B
24 24) What is the maximum number of electrons in a single 2 p orbital of an atom? A) 1 B) 2 C) 3 D) 4 E) 5
Answer: B
24 What kinds of molecules pass through a cell membrane most easily? A) large and hydrophobic B) small and hydrophobic C) large polar D) ionic E) monosaccharides such as glucose
Answer: B
25 Reduction of oxygen to form water occurs during A) photosynthesis only. B) respiration only. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration only.
Answer: B
25 Which of the following is a characteristic feature of a carrier protein in a plasma membrane? A) It is a peripheral membrane protein. B) It exhibits a specificity for a particular type of molecule. C) It requires the expenditure of cellular energy to function. D) It works against diffusion. E) It has few, if any, hydrophobic amino acids.
Answer: B
26 26) As N approaches K for a certain population, which of the following is predicted by the logistic equation? A) The growth rate will not change. B) The growth rate will approach zero. C) The population will show an Allee effect. D) The population will increase exponentially. E) The carrying capacity of the environment will increase.
Answer: B
26 Which of the following statements is true concerning catabolic pathways? A) They combine molecules into more energy-rich molecules. B) They supply energy, primarily in the form of ATP, for the cell's work. C) They are endergonic. D) They are spontaneous and do not need enzyme catalysis. E) They build up complex molecules such as protein from simpler compounds.
Answer: B
42 The termination phase of cell signaling requires which of the following? A) removal of the receptor B) activation of a different set of relay molecules C) converting ATP to camp D) incompatibility of the binding of the signal molecule to the receptor E) apoptosis
Answer: D
42 Where is ATP synthase located in the mitochondrion? A) cytosol B) electron transport chain C) outer membrane D) inner membrane E) mitochondrial matrix
Answer: D
27 27) A cell divides to produce two daughter cells that are genetically different. A) The statement is true for mitosis only. B) The statement is true for meiosis I only. C) The statement is true for meiosis II only. D) The statement is true for mitosis and meiosis I. E) The statement is true for mitosis and meiosis II.
Answer: B
27 27) What is the primary limiting factor for aquatic productivity? A) pressure B) lack of nutrients C) light availability D) herbivores E) competition
Answer: B
27 27) Which of the following is the most accepted hypothesis as to why invasive species take over communities into which they have been introduced? A) Invasive species are more aggressive than native species in competing for the limited resources of the environment. B) Invasive species are not held in check by the predators and agents of disease that have always been in place for the native species. C) Humans carefully select which species will outcompete nuisance native species. D) Invasive species have a higher reproductive potential than native species. E) Invasive species come from geographically isolated regions, so when they are introduced to regions where there is more competition, they thrive.
Answer: B
43 43) Of the following zoonotic diseases, which is most likely to be studied by a community ecologist? A) mad cow disease B) hantavirus C) AIDS D) avian flu E) trichinosis
Answer: D
27 According to Darwinian theory, which of the following exhibits the greatest fitness for evolutionary success? A) the species with the longest life B) the individuals within a population that have the greatest reproductive success C) the phylum with members that occupy the greatest number of habitats D) the community of organisms that is capable of living in the most nutrient-poor biome E) the organism that produces its own nutrients most efficiently
Answer: B
27 An atom with atomic number 12 would have what type of chemical behavior in bonding with other elements? A) It would form ions with a +1 charge. B) It would form ions with a +2 charge. C) It would form ions with a -1 charge. D) It would form ions with a -2 charge. E) It would form two covalent bonds with other atoms.
Answer: B
27 Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. Which of the following organelles contains these hydrolytic enzymes in animal cells? A) chloroplast B) lysosome C) central vacuole D) peroxisome E) glyoxysome
Answer: B
27 Why are human sex hormones considered to be lipids? A) They are essential components of cell membranes. B) They are not soluble in water. C) They are made of fatty acids. D) They are hydrophilic compounds. E) They contribute to atherosclerosis.
Answer: B
28 All of the following contain amino acids except A) hemoglobin. B) cholesterol. C) antibodies. D) enzymes. E) insulin.
Answer: B
28 Carbon dioxide (CO₂) is released during which of the following stages of cellular respiration? A) glycolysis and the oxidation of pyruvate to acetyl CoA B) oxidation of pyruvate to acetyl CoA and the citric acid cycle C) the citric acid cycle and oxidative phosphorylation D) oxidative phosphorylation and fermentation E) fermentation and glycolysis
Answer: B
43 In a plant leaf, the reactions that produce NADH occur in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but is not part of photosynthesis.
Answer: D
28 If a salamander relied on hydrogen bonds to cling to surfaces, what type of surface would cause the most problems for this animal? A) a surface coated with a thin film of water B) a surface made with carbon and hydrogen atoms covalently bonded together C) a surface made with carbon, hydrogen, and oxygen atoms covalently bonded together D) a surface made with carbon, hydrogen, nitrogen, and oxygen atoms covalently bonded together E) a surface made with silicon and oxygen atoms covalently bonded together
Answer: B
29 29) Carrying capacity is A) seldom reached by marine producers and consumers because of the vast resources of the ocean. B) the maximum population size that a particular environment can support. C) fixed for most species over most of their range most of the time. D) determined by density and dispersion data. E) the term used to describe the stress a population undergoes due to limited resources.
Answer: B
29 29) Independent assortment of chromosomes occurs. A) The statement is true for mitosis only. B) The statement is true for meiosis I only. C) The statement is true for meiosis II only. D) The statement is true for mitosis and meiosis I. E) The statement is true for mitosis and meiosis II.
Answer: B
29 29) Proteins coded by a very large family of related genes are active in the sensory transduction of A) gustatory stimuli. B) olfactory stimuli. C) visual stimuli. D) auditory stimuli. E) stimuli related to the position of the head.
Answer: B
29 What is the relationship between wavelength of light and the quantity of energy per photon? A) They have a direct, linear relationship. B) They are inversely related. C) They are logarithmically related. D) They are separate phenomena. E) They are only related in certain parts of the spectrum.
Answer: B
43 Ions diffuse across membranes through specific ion channels A) down their chemical gradients. B) down their concentration gradients. C) down the electrical gradients. D) down their electrochemical gradients. E) down the osmotic potential gradients.
Answer: D
2e⁻ for helium. Which of the following represents the 18O isotope of oxygen? A) 6p⁺, 8n⁰, 6e⁻ B) 8p⁺, 10n⁰, 8e⁻ C) 9p⁺, 9n⁰, 9e⁻ D) 7p⁺, 2n⁰, 9e⁻ E) 10p⁺, 8n⁰, 9e⁻
Answer: B
3 The partial negative charge in a molecule of water occurs because A) the oxygen atom acquires an additional electron. B) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus. C) the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms. D) the oxygen atom forms hybrid orbitals that distribute electrons unequally around the oxygen nucleus. E) one of the hydrogen atoms donates an electron to the oxygen atom.
Answer: B
30 30) It can be very difficult to select an angle for sneaking up to a grasshopper to catch it because grasshoppers have A) excellent hearing for detecting predators. B) compound eyes with multiple ommatidia. C) eyes with multiple fovea. D) a camera-like eye with multiple fovea. E) binocular vision.
Answer: B
30 30) Which of the following occurs in meiosis but not in mitosis? A) chromosome replication B) synapsis of chromosomes C) production of daughter cells D) alignment of chromosomes at the equator E) condensation of chromatin
Answer: B
30 During aerobic respiration, electrons travel downhill in which sequence? A) food → citric acid cycle → ATP → NAD⁺ B) food → NADH → electron transport chain → oxygen C) glucose → pyruvate → ATP → oxygen D) glucose → ATP → electron transport chain → NADH E) food → glycolysis → citric acid cycle → NADH → ATP
Answer: B
30 The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? A) rough ER B) smooth ER C) Golgi apparatus D) nuclear envelope E) transport vesicles
Answer: B
30 The method of scientific inquiry that describes natural structures and processes as accurately as possible through careful observation and the analysis of data is known as A) hypothesis-based science. B) discovery science. C) experimental science. D) quantitative science. E) qualitative science.
Answer: B
30 card image If an atom of sulfur (atomic number 16) were allowed to react with atoms of hydrogen (atomic number 1), which of the molecules below would be formed? [SEE IMAGE FOR CHOICES] Answer: B 31 What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen? A) 1 B) 2 C) 3 D) 4 E) 6
Answer: B
31 31) Compared to viewing a distant object, viewing an object held within 5 cm of the eye requires a lens that A) has been flattened, as a result of contraction of the ciliary muscles. B) has been made more spherical, as a result of contraction of the ciliary muscles. C) has been flattened, as a result of relaxation of the ciliary muscles. D) has been made more spherical, as a result of relaxation of the ciliary muscles. E) does not change its shape.
Answer: B
31 31) The word triage originated during World War I and was first used by French doctors in prioritizing patients based on the severity of their wounds, because there were more wounded soldiers in need of urgent care than there were resources to treat them. Conservation biologists have to make similar determinations with degraded ecosystems. Which of the following is the most important consideration when it comes to managing for maintenance of biodiversity? A) identifying large, high-profile vertebrates first, because steps to saving them would be most recognized by the public B) determining which species is most important for conserving biodiversity as a whole C) replanting suitable habitat for fauna D) assessing the economic costs and the gains for society E) maintaining optimum size of all populations in the ecosystem
Answer: B
31 Some photosynthetic bacteria (e.g., purple sulfur bacteria) have only photosystem I, whereas others (e.g., cyanobacteria) have both photosystem I and photosystem II. Which of the following might this observation imply? A) Photosystem II was selected against in some species. B) Photosynthesis with only photosystem I is more ancestral. C) Photosystem II may have evolved to be more photoprotective. D) Linear electron flow is more primitive than cyclic flow of electrons. E) Cyclic flow is more necessary than linear electron flow.
Answer: B
32 ) Polysaccharides, triacylglycerides, and proteins are similar in that they A) are synthesized from monomers by the process of hydrolysis. B) are synthesized from subunits by dehydration reactions. C) are synthesized as a result of peptide bond formation between monomers. D) are decomposed into their subunits by dehydration reactions. E) all contain nitrogen in their monomer building blocks.
Answer: B
32 32) Which of the following triggers the cell's passage past the G₂ checkpoint into mitosis? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
Answer: B
32 Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's A) entropy. B) activation energy. C) endothermic level. D) equilibrium point. E) free-energy content.
Answer: B
33 33) Rods exposed to light will A) depolarize due to the opening of sodium channels. B) hyperpolarize due to the closing of sodium channels. C) depolarize due to the opening of potassium channels. D) hyperpolarize due to the closing of potassium channels. E) fire one action potential for each photon received.
Answer: B
33 33) Which marine zone would have the lowest rates of primary productivity (photosynthesis)? A) pelagic B) abyssal C) neritic D) continental shelf E) intertidal
Answer: B
33 Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants? A) They serve as accessory pigments to increase light absorption. B) They protect against oxidative damage from excessive light energy. C) They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation. D) They reflect orange light and enhance red light absorption by chlorophyll. E) They take up and remove toxins from the groundwater.
Answer: B
33 In cellular respiration, the energy for most ATP synthesis is supplied by A) high energy phosphate bonds in organic molecules. B) a proton gradient across a membrane. C) converting oxygen to ATP. D) transferring electrons from organic molecules to pyruvate. E) generating carbon dioxide and oxygen in the electron transport chain.
Answer: B
33 In which of the following would there be the greatest need for osmoregulation? A) an animal connective tissue cell bathed in isotonic body fluid B) cells of a tidepool animal such as an anemone C) a red blood cell surrounded by plasma D) a lymphocyte before it has been taken back into lymph fluid E) a plant being grown hydroponically (in a watery mixture of designated nutrients)
Answer: B
34 34) A tetrad includes which of the following sets of DNA strands? A) two single-stranded chromosomes that have synapsed B) two sets of sister chromatids that have synapsed C) four sets of sister chromatids D) four sets of unique chromosomes E) eight sets of sister chromatids
Answer: B
34 34) What is the normal imprinting stimulus to a hatchling graylag goose? A) an image of a model of an adult graylag goose B) a nearby object that is moving away C) recognition of its biological mother D) any other adult of its own species E) any human
Answer: B
43 Research indicates that acid precipitation can damage living organisms by A) buffering aquatic systems such as lakes and streams. B) decreasing the H⁺ concentration of lakes and streams. C) increasing the OH⁻ concentration of lakes and streams. D) washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth. E) both decreasing the H⁺ concentration of lakes and streams and increasing the OH⁻ concentration of lakes and streams.
Answer: D
43 What type of covalent bond between amino acid side chains (R groups) functions in maintaining a polypeptide's specific three-dimensional shape? A) ionic bond B) hydrophobic interaction C) van der Waals interaction D) disulfide bond E) hydrogen bond
Answer: D
43 Which of the following explains most specifically the attraction of water molecules to one another? A) nonpolar covalent bond B) polar covalent bond C) ionic bond D) hydrogen bond E) hydrophobic interaction
Answer: D
44 In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and A) combine the hydrogen with water molecules to generate hydrogen peroxide. B) use the hydrogen to break down hydrogen peroxide. C) transfer the hydrogen to the mitochondria. D) transfer the hydrogen to oxygen molecules to generate hydrogen peroxide.
Answer: D
34 34) Which of the following pairs of reproductive strategies is consistent with energetic trade-off and reproductive success? A) Pioneer species of plants produce many very small, highly airborne seeds, whereas large elephants that are very good parents produce many offspring. B) Female rabbits that suffer high predation rates may produce several litters per breeding season, and coconuts produce few fruits, but most survive when they encounter proper growing conditions. C) Species that have to broadcast to distant habitats tend to produce seeds with heavy protective seed coats, and animals that are caring parents produce fewer offspring with lower infant mortality. D) Free-living insects lay thousands of eggs and provide no parental care, whereas flowers take good care of their seeds until they are ready to germinate. E) Some mammals will not reproduce when environmental resources are low so they can survive until conditions get better, and plants that produce many small seeds are likely found in stable environments.
Answer: B
35 35) Managing southwestern forests specifically for the red-cockaded woodpecker A) was wholeheartedly supported by the timber extraction industry. B) contributed to greater abundance and diversity of other forest bird species. C) caused other species of songbird to decline. D) involved strict fire suppression measures. E) involved the creation of fragmented forest habitat.
Answer: B
35 35) Trophic efficiency is A) the ratio of net secondary production to assimilation of primary production. B) the percentage of production transferred from one trophic level to the next. C) a measure of how nutrients are cycled from one trophic level to the next. D) usually greater than production efficiencies. E) about 90% in most ecosystems.
Answer: B
35 The primary role of oxygen in cellular respiration is to A) yield energy in the form of ATP as it is passed down the respiratory chain. B) act as an acceptor for electrons and hydrogen, forming water. C) combine with carbon, forming CO₂. D) combine with lactate, forming pyruvate. E) catalyze the reactions of glycolysis.
Answer: B
36 36) Species richness increases A) as we increase in altitude in equatorial mountains. B) as we travel southward from the North Pole. C) on islands as distance from the mainland increases. D) as depth increases in aquatic communities. E) as community size decreases.
Answer: B
36 36) Which of the following is true about the current research regarding forest fragmentation? A) Fragmented forests support a greater biodiversity because they result in the combination of forest-edge species and forest-interior species. B) Fragmented forests support a lesser biodiversity because the forested-adapted species leave, and only the edge and open-field species can occupy fragmented forests. C) Fragmented forests are the goal of conservation biologists who design wildlife preserves. D) Harvesting timber that results in forest fragmentation results in less soil erosion. E) The disturbance of timber extraction causes the species diversity to increase because of the new habitats created.
Answer: B
36 36) Which of the following shows the adaptive significance of cognitive mapping to animals that employ this type of learning? A) It increases the ability to visually recognize landmarks. B) Cognitive maps reduce the amount of detail required to remember the location of an object in the animal's environment. C) Animals can locate essential locations in their environment, such as nests, hazards, and feeding areas. D) Animals can outmaneuver predators by planning and memorizing getaway routes. E) Animals can determine their position relative to landmarks by a triangulation process.
Answer: B
36 The active site of an enzyme is the region that A) binds allosteric regulators of the enzyme. B) is involved in the catalytic reaction of the enzyme. C) binds noncompetitive inhibitors of the enzyme. D) is inhibited by the presence of a coenzyme or a cofactor.
Answer: B
37 37) Density-dependent inhibition is explained by which of the following? A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. C) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. D) As cells become more numerous, more and more of them enter the S phase of the cell cycle. E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism.
Answer: B
37 37) There are more species in tropical areas than in places more distant from the equator. This is probably a result of A) fewer predators. B) more intense annual solar radiation. C) more frequent ecological disturbances. D) fewer agents of disease. E) fewer predators, more intense annual solar radiation, more frequent ecological disturbances, and fewer agents of disease.
Answer: B
37 37) Which of the examples below provides appropriate abiotic and biotic factors that might determine the distribution of the species in question? A) the amount of nitrate and phosphate in the soil, and wildflower abundance and diversity B) the number of frost-free days, and competition between species of introduced grasses and native alpine grasses C) increased predation and decreased food availability, and a prairie dog population after a prairie fire D) available sunlight and increased salinity in the top few meters of the ocean, and the abundance and diversity of phytoplankton communities E) the pH and dissolved oxygen concentration, and the streams in which brook trout can live
Answer: B
37 In comparing covalent bonds and ionic bonds, which of the following would you expect? A) An atom can form covalent bonds with multiple partner atoms, but only a single ionic bond with a single partner atom. B) Covalent bonds and ionic bonds occupy opposite ends of a continuous spectrum, from nearly equal to completely unequal sharing of electrons. C) Both involve electrical attraction between the electrons of one atom and the nucleus of the other atom. D) Ionic interactions remain when covalent bonds are broken in water. Ionic bonds are much stronger than covalent bonds.
Answer: B
37 Thylakoids, DNA, and ribosomes are all components found in A) vacuoles. B) chloroplasts. C) mitochondria. D) lysosomes. E) nuclei.
Answer: B
38 38) For most terrestrial ecosystems, pyramids of numbers, biomass, and energy are essentially the samethey have a broad base and a narrow top. The primary reason for this pattern is that A) secondary consumers and top carnivores require less energy than producers. B) at each step, energy is lost from the system as a result of keeping the organisms alive. C) as matter passes through ecosystems, some of it is lost to the environment. D) biomagnification of toxic materials limits the secondary consumers and top carnivores. E) top carnivores and secondary consumers have a more general diet than primary producers.
Answer: B
38 38) Which pattern of reproduction is correctly paired with a species? A) iteroparityPacific salmon B) iteroparityelephant C) semelparityoak tree D) semelparityrabbit E) semelparity-polar bear
Answer: B
38 What maintains the secondary structure of a protein? A) peptide bonds B) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond C) disulfide bonds D) hydrophobic interactions E) hydrogen bonds between the R groups
Answer: B
38 card image Thalidomide and L-dopa, shown below, are examples of pharmaceutical drugs that occur as enantiomers, or molecules that A) have identical three-dimensional shapes. B) are mirror images of one another. C) are structural isomers. D) are mirror images of one another and have the same biological activity. E) are cis-trans isomers.
Answer: B
39 Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins? A) hydrophobic interactions B) disulfide bonds C) ionic bonds D) hydrogen bonds E) peptide bonds Answer: D 40 Which level of protein structure do the α helix and the β pleated sheet represent? A) primary B) secondary C) tertiary D) quaternary E) primary, secondary, tertiary, and quaternary
Answer: B
4 4) Artificial electrical stimulation of a human's capsaicin-sensitive neurons would likely produce the sensation of A) cold temperature. B) hot temperature. C) tactile stimulus. D) odor of pepper. E) deep pressure.
Answer: B
4 4) For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather than binary fission? A) Binary fission would not allow for the formation of new organisms. B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. C) Cell division would be faster than binary fission. D) Cell division allows for lower rates of error per chromosome replication. E) Binary fission would not allow the organism to have complex cells.
Answer: B
4 4) The proximate causes of behavior are interactions with the environment, but behavior is ultimately shaped by A) hormones. B) evolution. C) sexuality. D) pheromones. E) the nervous system.
Answer: B
4 4) Which of the following is a true statement about sexual vs. asexual reproduction? A) Asexual reproduction, but not sexual reproduction, is characteristic of plants and fungi. B) In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. C) In asexual reproduction, offspring are produced by fertilization without meiosis. D) Sexual reproduction requires that parents be diploid. E) Asexual reproduction produces only haploid offspring.
Answer: B
4 Differences among organisms are caused by A) large differences in elemental composition from organism to organism. B) differences in the types and relative amounts of organic molecules synthesized by each organism. C) differences in the elements that bond with carbon in each organism. D) differences in the sizes of the organic molecules in each organism. E) differences in inorganic compounds present in each organism.
Answer: B
4 For living organisms, which of the following is an important consequence of the first law of thermodynamics? A) The energy content of an organism is constant. B) The organism ultimately must obtain all of the necessary energy for life from its environment. C) The entropy of an organism decreases with time as the organism grows in complexity. D) Organisms grow by converting energy into organic matter. E) Life does not obey the first law of thermodynamics.
Answer: B
4 In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is A) the relative solubility of the component. B) the size and weight of the component. C) the percentage of carbohydrates in the component. D) the presence or absence of nucleic acids in the component. E) the presence or absence of lipids in the component.
Answer: B
4 Why does the oxidation of organic compounds by molecular oxygen to produce CO₂ and water release free energy? A) The covalent bonds in organic molecules and molecular oxygen have more kinetic energy than the covalent bonds in water and carbon dioxide. B) Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O). C) The oxidation of organic compounds can be used to make ATP. D) The electrons have a higher potential energy when associated with water and CO₂ than they do in organic compounds. E) The covalent bond in O₂ is unstable and easily broken by electrons from organic molecules.
Answer: B
41 41) Secondary consumers that can eat only primary consumers receive what percent of the energy fixed by primary producers in a typical field ecosystem? A) 0.1% B) 1% C) 10% D) 20% E) 80%
Answer: B
41 41) Which of the following is most likely to contribute to density-dependent regulation of populations? A) the removal of toxic waste by decomposers B) intraspecific competition for nutrients C) earthquakes D) floods E) fires
Answer: B
42 42) Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of A) parallel evolution. B) convergent evolution. C) allopatric speciation. D) introgression. E) gene flow.
Answer: B
42 42) Zoonotic disease A) is caused by suborganismal pathogens such as viruses, viroids, and prions only. B) is caused by pathogens that are transferred from other animals to humans by direct contact or by means of a vector. C) can only be spread from animals to humans through direct contact. D) can only be transferred from animals to humans by means of an intermediate host. E) is too specific to study at the community level, and studies of zoonotic pathogens are relegated to organismal biology.
Answer: B
42 In C₃ photosynthesis, the reactions that require ATP take place in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but is not part of photosynthesis.
Answer: B
42 In order to attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur in order for the final attachment to occur? A) The ATP must first have to attach to the tRNA. B) The binding of the first two molecules must cause a 3-D change that opens another active site on the enzyme. C) The ATP must be hydrolyzed to allow the amino acid to bind to the synthetase. D) The tRNA molecule must have to alter its shape in order to be able to fit into the active site with the other two molecules. E) The 3' end of the tRNA must have to be cleaved before it can have an attached amino acid.
Answer: B
43 43) After which checkpoint is the cell first committed to continue the cell cycle through M? A) G₀ B) G₁ C) G₂ D) S E) previous M
Answer: B
43 43) In which of the following terrestrial biome pairs are both parts dependent upon periodic burning? A) tundra and coniferous forest B) chaparral and savanna C) desert and savanna D) tropical forest and temperate broadleaf forest E) grassland and tundra
Answer: B
43 43) What is the biggest problem with selecting a site for a preserve? A) There is always a conflict about use of land set aside for preservation. B) Making a proper selection is difficult because currently the environmental conditions of almost any site change so quickly. C) Keystone species are difficult to identify in potential preserve sites. D) Only lands that are not useful to human activities are available for preserves. E) Most of the best sites are inaccessible by land transportation, so making roads to them is often prohibitively expensive.
Answer: B
43 It is possible to prepare vesicles from portions of the inner mitochondrial membrane. Which one of the following processes could still be carried on by this isolated inner membrane? A) the citric acid cycle B) oxidative phosphorylation C) glycolysis and fermentation D) reduction of NAD⁺ E) both the citric acid cycle and oxidative phosphorylation
Answer: B
43 Why isn't the mitochondrion classified as part of the endomembrane system? A) It is a static structure. B) Its structure is not derived from the ER or Golgi. C) It has too many vesicles. D) It is not involved in protein synthesis. E) It is not attached to the outer nuclear envelope.
Answer: B
43 card image Which of the structures illustrated above cannot form hydrogen bonds with water molecules? A) A B) B C) C D) D E) E
Answer: B
44 44) Fire suppression by humans A) will always result in an increase in species diversity in a given biome. B) can change the species composition within biological communities. C) will result ultimately in sustainable production of increased amounts of forest products for human use. D) is necessary for the protection of threatened and endangered forest species. E) is a management goal of conservation biologists to maintain the healthy condition of forest communities.
Answer: B
44 Protein kinases are enzymes that transfer the terminal phosphate from ATP to an amino acid residue on the target protein. Many are located on the plasma membrane as integral membrane proteins or peripheral membrane proteins. What purpose may be served by their plasma membrane localization? A) ATP is more abundant near the plasma membrane. B) They can more readily encounter and phosphorylate other membrane proteins. C) Membrane localization lowers the activation energy of the phosphorylation reaction. D) They flip back and forth across the membrane to access target proteins on either side. E) They require phospholipids as a cofactor.
Answer: B
44 Van der Waals interactions result when A) hybrid orbitals overlap. B) electrons are not symmetrically distributed in a molecule. C) molecules held by ionic bonds react with water. D) two polar covalent bonds react. E) a hydrogen atom loses an electron.
Answer: B
44 Why has C. elegans proven to be a useful model for understanding apoptosis? A) The animal has as many genes as complex organisms, but finding those responsible is easier than in a more complex organism. B) The nematode undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development. C) This plant has a long-studied aging mechanism that has made understanding its death just a last stage. D) While the organism ages, its cells die progressively until the whole organism is dead. E) All of its genes are constantly being expressed so all of its proteins are available from each cell.
Answer: B
44 Why is a scientific topic best discussed by people of varying points of view, a variety of subdisciplines, and diverse cultures? A) They can rectify each other's approach to make it truly scientific. B) Robust and critical discussion between diverse groups improves scientific thinking. C) Scientists can explain to others that they need to work in isolation to utilize the scientific method more productively. D) This is another way of making science more reproducible. E) Scientists need to exchange their ideas with other disciplines and cultures so that all groups are in consensus with the course of future research.
Answer: B
45 45) Which of the following could be a density-independent factor limiting human population growth? A) social pressure for birth control B) earthquakes C) plagues D) famines E) pollution
Answer: B
45 45) Which of the following statements best describes the interaction between fire and ecosystems? A) The likelihood of a wildfire occurring in a given ecosystem is highly predictable over the short term. B) Many kinds of plants and plant communities have adapted to frequent fires. C) The suppression of forest fires by man has prevented certain communities, such as grasslands, from reaching their climax stage. D) Chaparral communities have evolved to the extent that they rarely burn. E) Fire is unnatural in ecosystems and should be prevented.
Answer: B
45 Reactions that require CO₂ take place in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but is not part of photosynthesis.
Answer: B
45 The R group or side chain of the amino acid serine is -CH₂-OH. The R group or side chain of the amino acid leucine is -CH₂-CH-(CH₃)₂. Where would you expect to find these amino acids in a globular protein in aqueous solution? A) Serine would be in the interior, and leucine would be on the exterior of the globular protein. B) Leucine would be in the interior, and serine would be on the exterior of the globular protein. C) Both serine and leucine would be in the interior of the globular protein. D) Both serine and leucine would be on the exterior of the globular protein. E) Both serine and leucine would be in the interior and on the exterior of the globular protein.
Answer: B
45 card image The illustration above most probably represents A) a computer simulation of the structure of a eukaryotic cell. B) a map of a network of protein interactions within a eukaryotic cell. C) an inventory of all the genes in a fruit fly. D) an X-ray diffraction image of the nucleus and cytoplasm of a eukaryotic cell. E) a computer-generated map of the interaction of genes and cytoplasm in a prokaryotic cell.
Answer: B
46 How does a noncompetitive inhibitor decrease the rate of an enzyme reaction? A) by binding at the active site of the enzyme B) by changing the shape of the enzyme's active site C) by changing the free energy change of the reaction D) by acting as a coenzyme for the reaction E) by decreasing the activation energy of the reaction
Answer: B
46 Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean? A) Proton pumps must have evolved before any living organisms were present on Earth. B) Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. C) The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. D) Cells of each domain evolved proton pumps independently when oceans became more acidic. E) Proton pumps are necessary to all cell membranes.
Answer: B
46 card image What do these two plants have in common? A) adaptations to extreme heat B) adaptations to conserve water C) identical stem structures D) identical flower structures E) lack of photosynthesis
Answer: B
46 card image Which of the groups shown above is a carbonyl functional group? A) A B) B C) C D) D E) E
Answer: B
47 47) Agricultural lands frequently require nutrient augmentation because A) nitrogen-fixing bacteria are not as plentiful in agricultural soils because of the use of pesticides. B) the nutrients that become the biomass of plants are not cycled back to the soil on lands where they are harvested. C) land that is available for agriculture tends to be nutrient-poor. D) grains raised for feeding livestock must be fortified, and thus require additional nutrients. E) cultivation of agricultural land inhibits the decomposition of organic matter.
Answer: B
47 47) The oak tree pathogen, Phytophthora ramorum, has migrated 650 km in 10 years. West Nile virus spread from New York State to 46 other states in 5 years. The difference in the rate of spread is probably related to A) the lethality of each pathogen. B) the mobility of their hosts. C) the fact that viruses are very small. D) innate resistance. E) dormancy viability.
Answer: B
47 The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as A) metabolic inhibition. B) feedback inhibition. C) allosteric inhibition. D) noncooperative inhibition. E) reversible inhibition.
Answer: B
47 The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of A) active transport. B) an endergonic reaction coupled to an exergonic reaction. C) a reaction with a positive ΔG . D) osmosis. E) allosteric regulation.
Answer: B
47 Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell? A) Cell death would usually spread from one cell to the next via paracrine signals. B) Lysosomal enzymes exiting the dying cell would damage surrounding cells. C) Released cellular energy would interfere with the neighbors' energy budget. D) Bits of membrane from the dying cell could merge with neighbors and bring in foreign receptors. E) Neighboring cells would activate immunological responses.
Answer: B
45 45) Which of the following most accurately describes a cyclin? A) It is present in similar concentrations throughout the cell cycle. B) It is activated to phosphorylate by complexing with a Cdk. C) It decreases in concentration when MPF activity increases. D) It activates a Cdk molecule when it is in sufficient concentration. E) It activates a Cdk when its concentration is decreased.
Answer: D
45 45) Why is a pathogen generally more virulent in a new habitat? A) More pathogens tend to immigrate into newer habitats. B) Intermediate host species are more motile and transport pathogens to new areas. C) Pathogens evolve more efficient forms of reproduction in new environments. D) Hosts in new environments have not had a chance to become resistant to the pathogen through natural selection. E) New environments are almost always smaller in area so that transmission of pathogens is easily accomplished between hosts.
Answer: D
45 How does the cell multiply its peroxisomes? A) They bud off from the Golgi. B) They are brought into the cell from the environment. C) They are built de novo from cytosol materials. D) They split in two after they become sufficiently large. E) The cell synthesizes hydrogen peroxide and encloses it in a membrane.
Answer: D
45 Which of the following describes the events of apoptosis? A) The cell dies, it is lysed, its organelles are phagocytized, and its contents are recycled. B) Its DNA and organelles become fragmented, it dies, and it is phagocytized. C) The cell dies and the presence of its fragmented contents stimulates nearby cells to divide. D) Its DNA and organelles are fragmented, the cell shrinks and forms blebs, and the cell self-digests. E) Its nucleus and organelles are lysed, then the cell enlarges and bursts.
Answer: D
46 Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) Alzheimer's only B) Parkinson's only C) diabetes mellitus only D) Alzheimer's and Parkinson's only E) Alzheimer's, Parkinson's, and diabetes mellitus
Answer: D
46 Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? A) sites of energy production in cellular respiration B) membrane proteins C) ribosomes D) cytoskeletal structures E) cellulose fibers in the cell wall
Answer: D
47 47) Most of the ATP supplies for a skeletal muscle undergoing 1 hour of sustained exercise come from A) creatine phosphate. B) glycolysis. C) substrate phosphorylation. D) oxidative phosphorylation. E) de novo synthesis.
Answer: D
47 Three "turns" of the Calvin cycle generate a "surplus" molecule of glyceraldehyde 3-phosphate (G3P). Which of the following is a consequence of this? A) Formation of a molecule of glucose would require nine "turns." B) G3P more readily forms sucrose and other disaccharides than it does monosaccharides. C) Some plants would not taste sweet to us. D) The formation of sucrose and starch in plants involves assembling G3P molecules, with or without further rearrangements. E) Plants accumulate and store G3P.
Answer: D
48 An organism with a cell wall would most likely be unable to take in materials through A) diffusion. B) osmosis. C) active transport. D) phagocytosis. E) facilitated diffusion.
Answer: D
48 Chemiosmotic ATP synthesis (oxidative phosphorylation) occurs in A) all cells, but only in the presence of oxygen. B) only eukaryotic cells, in the presence of oxygen. C) only in mitochondria, using either oxygen or other electron acceptors. D) all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors. E) all cells, in the absence of respiration.
Answer: D
48 In the process of carbon fixation, RuBP attaches a CO₂ to produce a six-carbon molecule, which is then split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P), what more needs to happen to complete the Calvin cycle? A) addition of a pair of electrons from NADPH B) inactivation of RuBP carboxylase enzyme C) regeneration of ATP from ADP D) regeneration of RuBP E) regeneration of NADP⁺
Answer: D
48 What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms? A) 2 B) 3 C) 4 D) 6 E) 8
Answer: D
49 49) A research team began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away? A) The cells originated in the nervous system. B) The cells are unable to form spindle microtubules. C) They have altered series of cell cycle phases. D) The cells show characteristics of tumors. E) They were originally derived from an elderly organism.
Answer: D
49 49) Studying species transplants is a way that ecologists A) determine the abundance of a species in a specified area. B) determine the distribution of a species in a specified area. C) develop mathematical models for distribution and abundance of organisms. D) determine if dispersal is a key factor in limiting distribution of organisms. E) consolidate a landscape region into a single ecosystem.
Answer: D
49 49) The "motor unit" in vertebrate skeletal muscle refers to A) one actin binding site and its myosin partner. B) one sarcomere and all of its actin and myosin filaments. C) one myofibril and all of its sarcomeres. D) one motor neuron and all of the muscle fibers on which it has synapses. E) an entire muscle.
Answer: D
49 Allosteric enzyme regulation is usually associated with A) lack of cooperativity. B) feedback inhibition. C) activating activity. D) an enzyme with more than one subunit. E) the need for cofactors.
Answer: D
49 Increased atmospheric CO₂ concentrations might have what effect on seawater? A) Seawater will become more acidic, and bicarbonate concentrations will decrease. B) Seawater will become more alkaline, and carbonate concentrations will decrease. C) There will be no change in the pH of seawater, because carbonate will turn to bicarbonate. D) Seawater will become more acidic, and carbonate concentrations will decrease. E) Seawater will become more acidic, and carbonate concentrations will increase.
Answer: D
49 card image 49) Which of the following statements is a valid conclusion of this experiment? A) Balanus can only survive in the lower intertidal zone, because it is unable to resist desiccation. B) Balanus is inferior to Chthamalus in competing for space on intertidal zone rocks. C) The two species of barnacles do not compete with each other because they feed at different times of day. D) When Balanus is removed, it can be observed that the realized niche of Chthamalus is smaller than its fundamental niche. E) These two species of barnacle do not show competitive exclusion. F) If Chthamalus were removed, Balanus's fundamental niche would become larger.
Answer: D
48 48) What explains anchorage dependence of animal cells in vitro or in vivo? A) attachment of spindle fibers to centrioles B) response of the plasma membrane to cell cycle controls C) the makeup of the extracellular matrix of the substrate D) the binding of cell-surface phospholipids to those of adjoining cells E) the binding of cell-surface phospholipids to the substrate
Answer: B
49 49) Which of the life cycles is typical for most fungi and some protists? A) I only B) II only C) III only D) I and II E) I and III
Answer: B
49 49) Why does the 2009 U.S. population continue to grow even though the United States has essentially established a ZPG? A) emigration B) immigration C) better sanitation D) baby boomer reproduction E) the 2007-2009 economic recession
Answer: B
49 White blood cells engulf bacteria through what process? A) exocytosis B) phagocytosis C) pinocytosis D) osmosis E) receptor-mediated exocytosis
Answer: B
5 5) Resource partitioning would be most likely to occur between A) sympatric populations of a predator and its prey. B) sympatric populations of species with similar ecological niches. C) sympatric populations of a flowering plant and its specialized insect pollinator. D) allopatric populations of the same animal species. E) allopatric populations of species with similar ecological niches.
Answer: B
49 of the following is true for this reaction? 3 H₂ + N₂ ↔ 2 NH₃ A) The reaction is nonreversible. B) Hydrogen and nitrogen are the reactants of the reverse reaction. C) Hydrogen and nitrogen are the products of the forward reaction. D) Ammonia is being formed and decomposed. E) Hydrogen and nitrogen are being decomposed.
Answer: D
5 5) Suppose a biologist can separate one of a dozen pieces of chromatin from a eukaryotic (animal) nucleus. It might consist of which of the following? A) one-twelfth of the genes of the organism B) two chromosomes, each with six chromatids C) a single circular piece of DNA D) two long strands of DNA plus proteins E) two chromatids attached together at a centromere
Answer: D
5 5) Uniform spacing patterns in plants such as the creosote bush are most often associated with A) chance. B) patterns of high humidity. C) the random distribution of seeds. D) competitive interaction between individuals of the same population. E) the concentration of nutrients within the population's range.
Answer: D
5 5) Which of the following provides the best evidence of a biodiversity crisis? A) the incursion of a non-native species B) increasing pollution levels C) decrease in regional productivity D) high rate of extinction E) climate change
Answer: D
5 In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? A) autotrophs and heterotrophs B) producers and primary consumers C) photosynthesizers D) autotrophs E) green plants
Answer: D
5 Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? A) Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. B) Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe. C) Living organisms do not follow the laws of thermodynamics. D) As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth. E) Living organisms are able to transform energy into entropy.
Answer: D
50 50) In part III of Figure 13.1, the progression of events corresponds to which of the following series? A) zygote, mitosis, gametophyte, mitosis, fertilization, zygote, mitosis B) sporophyte, meiosis, spore, mitosis, gametophyte, mitosis, gametes, fertilization C) fertilization, mitosis, multicellular haploid, mitosis, spores, sporophyte D) gametophyte, meiosis, zygote, spores, sporophyte, zygote E) meiosis, fertilization, zygote, mitosis, adult, meiosis
Answer: B
50 50) The muscles of a recently deceased human can remain in a contracted state, termed rigor mortis, for several hours, due to the lack of A) phosphorylated myosin. B) ATP needed to break actin-myosin bonds. C) calcium ions needed to bind to troponin. D) oxygen supplies needed for myoglobin. E) sodium ions needed to fire action potentials.
Answer: B
50 The students plan to gather data from the project. Which of the following would be the best way to present what they gather from experimental groups as opposed to controls? A) qualitatively, noting color, size, and so on B) measuring the number of new colonies formed during every 12-hour period C) counting the number of new colonies after a week D) measuring the size of each new colony in millimeters (mm) of length E) measuring the dry weight of all new colonies in grams
Answer: B
50 What is proton-motive force? A) the force required to remove an electron from hydrogen B) the force exerted on a proton by a transmembrane proton concentration gradient C) the force that moves hydrogen into the intermembrane space D) the force that moves hydrogen into the mitochondrion E) the force that moves hydrogen to NAD⁺
Answer: B
51 51) Calcium ions initiate sliding of filaments in skeletal muscles by A) breaking the actin-myosin cross-bridges. B) binding to the troponin complex, which then relocates tropomyosin. C) transmitting action potentials across the neuromuscular junction. D) spreading action potentials through the T tubules. E) reestablishing the resting membrane potential following an action potential.
Answer: B
51 51) Which of the following statements is correct about biogeochemical cycling? A) The phosphorus cycle involves the recycling of atmospheric phosphorus. B) The phosphorus cycle involves the weathering of rocks. C) The carbon cycle is a localized cycle that primarily involves the burning of fossil fuels. D) The carbon cycle has maintained a constant atmospheric concentration of CO₂ for the past million years. E) The nitrogen cycle involves movement of diatomic nitrogen between the biotic and abiotic components of the ecosystem.
Answer: B
51 Photorespiration occurs when rubisco reacts RuBP with A) CO₂. B) O₂. C) glyceraldehyde 3-phosphate. D) 3-phosphoglycerate. E) NADPH.
Answer: B
51 Which of the following correctly describes any reaction that has reached chemical equilibrium? A) The concentration of the reactants equals the concentration of the products. B) The rate of the forward reaction is equal to the rate of the reverse reaction. C) All of the reactants have been converted to the products of the reaction. D) All of the products have been converted to the reactants of the reaction. E) Both the forward and the reverse reactions have stopped with no net effect on the concentration of the reactants and the products.
Answer: B
51 of the following techniques uses the amino acid sequences of polypeptides to predict a protein's three-dimensional structure? A) X-ray crystallography B) bioinformatics C) analysis of amino acid sequence of small fragments D) NMR spectroscopy E) high-speed centrifugation
Answer: B
52 52) Muscle cells are stimulated by neurotransmitters released from the synaptic terminals of A) T tubules. B) motor neuron axons. C) sensory neuron axons. D) motor neuron dendrites. E) sensory neuron dendrites.
Answer: B
52 52) Pair-bonding in a population of prairie voles can be prevented by A) the ensuing confusion caused by introducing meadow voles. B) administering a drug that inhibits the brain receptor for vasopressin in the CNS of males. C) administering a drug that turns on ADH receptor sites in male voles. D) dying the coat color from brown to blond in either male or female prairie voles. E) allowing the population size to reach critically low levels.
Answer: B
52 Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? A) cessation of cellular protein synthesis B) localization of enzymes into specific organelles or membranes C) exporting enzymes out of the cell D) connecting enzymes into large aggregates E) hydrophobic interactions
Answer: B
53 What is the term used for a protein molecule that assists in the proper folding of other proteins? A) tertiary protein B) chaperonin C) enzyme protein D) renaturing protein E) denaturing protein
Answer: B
53 Why are C₄ plants able to photosynthesize with no apparent photorespiration? A) They do not participate in the Calvin cycle. B) They use PEP carboxylase to initially fix CO₂. C) They are adapted to cold, wet climates. D) They conserve water more efficiently. E) They exclude oxygen from their tissues.
Answer: B
53 card image Refer to the figure above (first three rows of the periodic table). If life arose on a planet where carbon is absent, which element might fill the role of carbon? A) boron B) silicon C) nitrogen D) aluminum E) phosphorus
Answer: B
53 card image Use the following diagram of a hypothetical food web to answer the following question. The arrows represent the transfer of food energy between the various trophic levels. Figure 54.3 53) Which letter represents an organism that could be a producer? A) A B) B C) C D) D E) E
Answer: B
53 card image Which molecules shown above contain a carbonyl group? A) A and B B) B and C C) B, C, and D D) D and E E) E and A
Answer: B
54 A major group of G protein-coupled receptors contains seven transmembrane α helices. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior face or on the cytosol face of the membrane. The loop on the cytosol side between helices 5 and 6 is usually substantially longer than the others. Where would you expect to find the carboxyl end? A) at the exterior surface B) at the cytosol surface C) connected with the loop at H5 and H6 D) between the membrane layers
Answer: B
54 DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase? A) The two strands of the double helix would separate. B) The phosphodiester bonds between deoxyribose sugars would be broken. C) The purines would be separated from the deoxyribose sugars. D) The pyrimidines would be separated from the deoxyribose sugars. E) All bases would be separated from the deoxyribose sugars.
Answer: B
54 card image The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all. 54) Which climograph shows the climate for location 5? A) A B) C C) D D) E E) H
Answer: B
55 Questions 55 - 64 are from the end-of-chapter "Test Your Understanding" section in Chapter 1 of the textbook. All the organisms on your campus make up A) an ecosystem. B) a community. C) a population. D) an experimental group. E) a taxonomic domain.
Answer: B
55 Which of the following statements about the 5' end of a polynucleotide strand of DNA is correct? A) The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. B) The 5' end has a phosphate group attached to the number 5 carbon of ribose. C) The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base. D) The 5' end has a carboxyl group attached to the number 5 carbon of ribose. E) The 5' end is the fifth position on one of the nitrogenous bases.
Answer: B
55 card image How many grams of the compound in the figure above would be required to make 1 L of a 0.5 M solution? (carbon = 12, oxygen = 16, hydrogen = 1) A) 29 B) 30 C) 60 D) 150 E) 342
Answer: B
55 card image Which molecule shown above has a carbonyl functional group in the form of an aldehyde? A) A B) B C) C D) D E) E
Answer: B
55 card image You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in Figure 13.3. Refer to the graph to answer the following questions. 55) Which sample might represent an animal cell in the G2 phase of the cell cycle? A) I B) II C) III D) both I and II E) either II or III
Answer: B
56 56) The presence of altruistic behavior is most likely due to kin selection, a theory maintaining that A) aggression between sexes promotes the survival of the fittest individuals. B) genes enhance survival of copies of themselves by directing organisms to assist others who share those genes. C) companionship is advantageous to animals because in the future they can help each other. D) critical thinking abilities are normal traits for animals and they have arisen, like other traits, through natural selection. E) natural selection has generally favored the evolution of exaggerated aggressive and submissive behaviors to resolve conflict without grave harm to participants.
Answer: B
56 56) What is the goal of restoration ecology? A) to replace a ruined ecosystem with a more suitable ecosystem for that area B) to speed up the restoration of a degraded ecosystem C) to completely restore a disturbed ecosystem to its former undisturbed state D) to prevent further degradation by protecting an area with park status E) to manage competition between species in human-altered ecosystems
Answer: B
56 One of the primary functions of RNA molecules is to A) transmit genetic information to offspring. B) function in the synthesis of proteins. C) make a copy of itself, thus ensuring genetic continuity. D) act as a pattern or blueprint to form DNA. E) form the genes of higher organisms.
Answer: B
56 card image Which drawing in the figure above depicts the electron configuration of an atom capable of forming three covalent bonds with other atoms? A) A B) B C) C D) D E) E
Answer: B
57 Affinity chromatography is a method that can be used to purify cell-surface receptors, while they retain their hormone-binding ability. A ligand (hormone) for a receptor of interest is chemically linked to polystyrene beads. A solubilized preparation of membrane proteins is passed over a column containing these beads. Only the receptor binds to the beads. When an excess of the ligand (hormone) is poured through the column after the receptor binding step, what do you expect will occur? A) The ligand will attach to those beads that have the receptor and remain on the column. B) The ligand will cause the receptor to be displaced from the beads and eluted out. C) The ligand will attach to the bead instead of the receptor. D) The ligand will cause the bead to lose its affinity by changing shape. E) The reaction will cause a pH change due to electron transfer.
Answer: B
57 card image 57) Which number represents DNA synthesis? A) I B) II C) III D) IV E) V
Answer: B
57 card image In the figure, why does the reaction rate plateau at higher reactant concentrations? A) Feedback inhibition by product occurs at high reactant concentrations. B) Most enzyme molecules are occupied by substrate at high reactant concentrations. C) The reaction nears equilibrium at high reactant concentrations. D) The activation energy for the reaction increases with reactant concentration. E) The rate of the reverse reaction increases with reactant concentration.
Answer: B
57 card image The diagram shows a generalized cross section of the marine environment with various zones labeled with letters. Choose the letter that best answers the question. Letters may be used once, more than once, or not at all 57) Which zone produces the most global oxygen gas? A) A B) B C) C D) D E) E
Answer: B
58 58) Sustained muscle contraction without relaxation between successive stimuli is called A) tonus. B) fused tetanus. C) an all-or-none response. D) fatigue. E) a spasm.
Answer: B
58 Affinity chromatography is a method that can be used to purify cell-surface receptors, while they retain their hormone-binding ability. A ligand (hormone) for a receptor of interest is chemically linked to polystyrene beads. A solubilized preparation of membrane proteins is passed over a column containing these beads. Only the receptor binds to the beads. This method of affinity chromatography would be expected to collect which of the following? A) molecules of the hormone B) molecules of purified receptor C) G proteins D) assorted membrane proteins E) hormone-receptor complexes
Answer: B
58 card image 58) Which number represents the point in the cell cycle during which the chromosomes are replicated? A) I B) II C) III D) IV E) V
Answer: B
58 card image Which component is a glycolipid? A) A B) B C) C D) D E) E
Answer: B
58 card image Which molecule shown above can form a dimer linked by a covalent bond? A) A B) B C) C D) D E) E
Answer: B
59 The ATP made during fermentation is generated by which of the following? A) the electron transport chain B) substrate-level phosphorylation C) chemiosmosis D) oxidative phosphorylation E) aerobic respiration
Answer: B
59 Which of the following are nitrogenous bases of the pyrimidine type? A) guanine and adenine B) cytosine and uracil C) thymine and guanine D) ribose and deoxyribose E) adenine and thymine
Answer: B
59 card image 59) In the territorial behavior of the stickleback fish, the red belly of one male that elicits attack from another male is functioning as A) a pheromone. B) a sign stimulus. C) a fixed action pattern. D) a search image. E) an imprint stimulus.
Answer: B
59 card image Which drawing in the figure above depicts an atom with a valence of 3? A) A B) B C) C D) D E) E
Answer: B
6 6) At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? A) prophase B) metaphase C) anaphase D) telophase E) interphase
Answer: B
6 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of which type of regulation? A) a bioinformatic system B) positive feedback C) negative feedback D) feedback inhibition E) enzymatic catalysis
Answer: B
6 Stanley Miller's 1953 experiments proved that A) life arose on Earth from simple inorganic molecules. B) organic molecules can be synthesized abiotically under conditions that may have existed on early Earth. C) life arose on Earth from simple organic molecules, with energy from lightning and volcanoes. D) the conditions on early Earth were conducive to the origin of life. E) the conditions on early Earth were conducive to the abiotic synthesis of organic molecules.
Answer: B
6 Which of the following effects is produced by the high surface tension of water? A) Lakes don't freeze solid in winter, despite low temperatures. B) A water strider can walk across the surface of a small pond. C) Organisms resist temperature changes, although they give off heat due to chemical reactions. D) Evaporation of sweat from the skin helps to keep people from overheating. E) Water flows upward from the roots to the leaves in plants.
Answer: B
60 Which of the following are nitrogenous bases of the purine type? A) cytosine and guanine B) guanine and adenine C) adenine and thymine D) thymine and uracil E) uracil and cytosine
Answer: B
60 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following terms best describes the forward reaction in Figure 8.1? A) endergonic, ∆G > 0 B) exergonic, ∆G < 0 C) endergonic, ∆G < 0 D) exergonic, ∆G > 0 E) chemical equilibrium, ∆G = 0
Answer: B
61 61) During a field trip, an instructor touched a moth resting on a tree trunk. The moth raised its forewings to reveal large eyespots on its hind wings. The instructor asked why the moth lifted its wings. One student answered that sensory receptors had fired and triggered a neuronal reflex culminating in the contraction of certain muscles. A second student responded that the behavior might frighten predators. Which statement best describes these explanations? A) The first explanation is correct, but the second is incorrect. B) The first explanation refers to proximate causation, whereas the second refers to ultimate causation. C) The first explanation is biological, whereas the second is philosophical. D) The first explanation is testable as a scientific hypothesis, whereas the second is not. E) Both explanations are reasonable and simply represent a difference of opinion.
Answer: B
61 A controlled experiment is one that A) proceeds slowly enough that a scientist can make careful records of the results. B) tests experimental and control groups in parallel. C) is repeated many times to make sure the results are accurate. D) keeps all variables constant. E) is supervised by an experienced scientist.
Answer: B
61 The next question presumes that you have at least once visited and have some knowledge of the fast-food restaurant McDonald's. Use your knowledge of McDonald's and your understanding of community ecology to answer the following questions about an ecological community, McDonaldland. 61) According to the McDonaldland scenario, which of the following would best define an ecological community? A) all of the sandwiches sold at McDonaldland B) the entire menu at McDonaldland C) all of the fast-food restaurants in the United States D) the condiments served at McDonaldland E) the breakfast menu at McDonaldland
Answer: B
61 card image The following questions refer to Figure 53.3, which depicts the age structure of three populations. 61) Which population(s) is (are) in the process of decreasing? A) I B) II C) III D) I and II E) II and III
Answer: B
61 card image The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. At the beginning of the experiment, A) side A is hypertonic to side B. B) side A is hypotonic to side B. C) side A is isotonic to side B. D) side A is hypertonic to side B with respect to glucose. E) side A is hypotonic to side B with respect to sodium chloride.
Answer: B
62 62) One way to understand how early environment influences differing behaviors in similar species is through the "cross-fostering" experimental technique. Suppose that the curly-whiskered mud rat differs from the bald mud rat in several ways, including being much more aggressive. How would you set up a cross-fostering experiment to determine if environment plays a role in the curly-whiskered mud rat's aggression? A) You would cross curly-whiskered mud rats and bald mud rats and hand-rear the offspring to see if any grew up to be aggressive. B) You would place newborn curly-whiskered mud rats with bald mud rat parents, place newborn bald mud rats with curly-whiskered mud rat parents, and let some mud rats of both species be raised by their own species. Then you would compare the outcomes. C) You would remove the offspring of curly-whiskered mud rats and bald mud rats from their parents, raise them in the same environment, and then compare the outcomes. D) You would see if curly-whiskered mud rats bred true for aggression. E) You would replace normal newborn mud rats with deformed newborn mud rats to see if it triggered an altruistic response.
Answer: B
62 A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of A) 120 adenine and 120 uracil molecules. B) 120 thymine and 120 adenine molecules. C) 120 cytosine and 120 thymine molecules. D) 120 adenine and 120 cytosine molecules. E) 120 guanine and 120 thymine molecules.
Answer: B
63 card image Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species) 63) Examine this food web for a particular terrestrial ecosystem. Species C is toxic to predators. Which species is most likely to benefit from being a mimic of C? A) A B) B C) C D) D E) E
Answer: B
64 The bonds that are broken when water vaporizes are A) ionic bonds. B) hydrogen bonds between water molecules. C) covalent bonds between atoms within water molecules. D) polar covalent bonds. E) nonpolar covalent bonds.
Answer: B
64 card image How many electrons does an atom of sulfur have in its valence shell (see the figure above)? A) 4 B) 6 C) 8 D) 16 E) 32
Answer: B
64 card image If the carbon atom of the incoming CO₂ molecule is labeled with a radioactive isotope of carbon, which organic molecules will be radioactively labeled after one cycle? A) C only B) B, C, D, and E C) C, D, and E only D) B and C only E) B and D only
Answer: B
65 65) According to Hamilton's rule, A) natural selection does not favor altruistic behavior that causes the death of the altruist. B) natural selection favors altruistic acts when the resulting benefit to the beneficiary, corrected for relatedness, exceeds the cost to the altruist. C) natural selection is more likely to favor altruistic behavior that benefits an offspring than altruistic behavior that benefits a sibling. D) the effects of kin selection are larger than the effects of direct natural selection on individuals. E) altruism is always reciprocal.
Answer: B
65 65) Which lake zone would be absent in a very shallow lake? A) benthic zone B) aphotic zone C) pelagic zone D) littoral zone E) limnetic zone
Answer: B
65 If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence A) 5'TAACGT3'. B) 5'TGCAAT3'. C) 5'UAACGU3'. D) 3'UAACGU5'. E) 5'UGCAAU3'.
Answer: B
65 Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because A) only target cells retain the appropriate DNA segments. B) intracellular receptors are present only in target cells. C) most cells lack the Y chromosome required. D) only target cells possess the cytosolic enzymes that transduce the testosterone. E) only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.
Answer: B
65 Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student—faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 65) Which of the following questions might be answered by such a method? A) How many cells are produced by the culture per hour? B) What is the length of the S phase of the cell cycle? C) When is the S chromosome synthesized? D) How many picograms of DNA are made per cell cycle? E) When do spindle fibers attach to chromosomes?
Answer: B
65 Organic chemistry is currently defined as A) the study of compounds made only by living cells. B) the study of carbon compounds. C) the study of vital forces. D) the study of natural (as opposed to synthetic) compounds. E) the study of hydrocarbons.
Answer: B
65 Why is glycolysis considered to be one of the first metabolic pathways to have evolved? A) It produces much less ATP than does oxidative phosphorylation. B) It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms. C) It is found in prokaryotic cells but not in eukaryotic cells. D) It relies on chemiosmosis, which is a metabolic mechanism present only in the first cells' prokaryotic cells. E) It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.
Answer: B
65 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in Figure 8.1? A) a B) b C) c D) d E) e
Answer: B
65 card image Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes? A) A and B B) B C) C D) D E) D and E
Answer: B
66 66) Homologous chromosomes move toward opposite poles of a dividing cell during A) mitosis. B) meiosis I. C) meiosis II. D) fertilization. E) binary fission.
Answer: B
66 What is the structural feature that allows DNA to replicate? A) sugar-phosphate backbone B) complementary pairing of the nitrogenous bases C) disulfide bonding (bridging) of the two helixes D) twisting of the molecule to form an α helix E) three-component structure of the nucleotides
Answer: B
50 50) This term refers to the reflecting and absorption of infrared radiation by atmospheric methane, carbon dioxide, and water. A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: D
50 50) Which of the following is an example of a local biogeochemical cycle? A) O₂ released by oak trees in a forest B) CO₂ absorbed by phytoplankton in the open ocean C) excess NO₃- converted to N₂ by denitrifying soil bacteria D) phosphorous being absorbed from the soil by a corn plant E) organic carbon remains of a leaf being converted to CO₂ by a fungus
Answer: D
50 How would acidification of seawater affect marine organisms? A) Acidification would increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals. B) Acidification would decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals. C) Acidification would increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals. D) Acidification would decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals. E) Acidification would increase dissolved bicarbonate concentrations, and cause increased calcification of corals and shellfish.
Answer: D
50 In a normal cellular protein, where would you expect to find a hydrophobic amino acid like valine? A) in the interior of the folded protein, away from water B) on the exterior surface of the protein, interacting with water C) in the transmembrane portion interacting with lipid fatty acid chains D) in the interior of the folded protein, away from water, or in a transmembrane portion interacting with lipid fatty acid chains E) anywhere in the protein, with equal probability
Answer: D
50 The phylogenetic distribution of the enzyme rubisco is limited to A) C₃ plants only. B) C₃ and C₄ plants. C) all photosynthetic eukaryotes. D) all known photoautotrophs, both bacterial and eukaryotic. E) all living cells.
Answer: D
51 card image The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all. 51) Which climograph shows the climate for location 2? A) B B) C C) D D) F E) H
Answer: D
52 52) Which of the following properly links the nutrient to its reservoir? A) nitrogenionic nitrogen in the soil B) wateratmospheric water vapor C) carbondissolved CO₂ in aquatic ecosystems D) phosphoroussedimentary rocks E) All of the options are correct.
Answer: D
52 card image Which of the following types of signaling is represented in the figure? A) autocrine B) paracrine C) hormonal D) synaptic E) long distance
Answer: D
53 If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? A) limbs, hearts, areas with a good deal of contraction B) microvilli, alveoli, and glomeruli: cellular projections that increase surface area C) all ducts, such as those from salivary or sebaceous glands, that transport fluids D) sperm, larynx, and trachea: cells and tissues that contain flagella or cilia E) phagocytic cells and white blood cells that exhibit amoeboid movement
Answer: D
53 card image 53) Which curve best describes survivorship in a marine crustacean that molts? A) A B) B C) C D) D E) E
Answer: D
53 card image Figure 13.2 of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis 53) Which diagram(s) represent anaphase II of meiosis? A) II only B) III only C) IV only D) V only E) either II or V
Answer: D
53 card image The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all. 53) Which climograph shows the climate for location 4? A) A B) B C) C D) E E) G
Answer: D
55 55) A skeletal muscle with abnormally low levels of calcium ions would be impaired in A) ATP hydrolysis. B) the initiation of an action potential. C) maintaining its resting membrane potential. D) initiating contraction. E) its ability to sustain glycolysis.
Answer: D
55 card image 55) In the figure above, mitosis is represented by which numbered part(s) of the cycle? A) I B) II C) III D) IV E) V
Answer: D
56 A major group of G protein-coupled receptors contains seven transmembrane α helices. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior face or on the cytosol face of the membrane. The loop on the cytosol side between helices 5 and 6 is usually substantially longer than the others. If you wish to design an experiment to block the G protein-coupled receptor interaction, the block would preferentially affect which of the following? A) the exterior (cytoplasmic) end of the receptor B) the cytosolic end of the receptor C) the phospholipid's transmembrane domain D) the amino acid sequence in the binding site for the G protein E) the amino acids in the binding site for the transduction molecules
Answer: D
56 Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? A) brain, organ system, nerve cell, nervous tissue B) organ system, nervous tissue, brain C) organism, organ system, tissue, cell, organ D) nervous system, brain, nervous tissue, nerve cell E) organ system, tissue, molecule, cell
Answer: D
56 card image How many grams of the compound in the figure above would be required to make 2.5 L of a 1 M solution? (carbon = 12, oxygen = 16, hydrogen = 1) A) 29 B) 30 C) 60 D) 150 E) 342
Answer: D
57 If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur? A) Photosynthetic efficiency would be reduced at low light intensities. B) Cells would carry on the Calvin cycle at a much slower rate. C) Less ATP would be generated. D) There would be more light-induced damage to the cells. E) Less oxygen would be produced.
Answer: D
57 card image A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in Figure 13.4. 57) A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, her resulting eggs (ova) may have which of the following? A) either two number 12 chromosomes with blue genes or two with orange genes B) either two number 19 chromosomes with long genes or two with short genes C) either one blue or one orange gene in addition to either one long or one short gene D) one chromosome 12 with one blue gene and one chromosome 19 with one long gene
Answer: D
57 card image Which molecule shown above can increase the concentration of hydrogen ions in a solution and is therefore an organic acid? A) A B) B C) C D) D E) E
Answer: D
58 58) The central concept of sociobiology is that A) human behavior is rigidly predetermined. B) the behavior of an individual cannot be modified. C) human behavior consists mainly of fixed action patterns. D) most aspects of our social behavior have an evolutionary basis. E) the social behavior of humans is homologous to the social behavior of other social animals.
Answer: D
58 Which metabolic pathway is common to both cellular respiration and fermentation? A) the oxidation of pyruvate to acetyl CoA B) the citric acid cycle C) oxidative phosphorylation D) glycolysis E) chemiosmosis
Answer: D
58 card image Flycatcher birds that migrate from Africa to Europe feed their nestlings a diet that is almost exclusively moth caterpillars. The graph below shows the mean dates of arrival, bird hatching, and peak caterpillar season for the years 1980 and 2000. 58) The shift in the peak of caterpillar season is most likely due to A) pesticide use. B) earlier migration returns of flycatchers. C) an innate change in the biological clock of the caterpillars. D) global warming. E) acid precipitation in Europe.
Answer: D
66 card image Human immunodeficiency virus (HIV) infects cells that have both CD4 and CCR5 cell surface molecules. The viral nucleic acid molecules are enclosed in a protein capsid, and the protein capsid is itself contained inside an envelope consisting of a lipid bilayer membrane and viral glycoproteins. One hypothesis for viral entry into cells is that binding of HIV membrane glycoproteins to CD4 and CCR5 initiates fusion of the HIV membrane with the plasma membrane, releasing the viral capsid into the cytoplasm. An alternative hypothesis is that HIV gains entry into the cell via receptor-mediated endocytosis, and membrane fusion occurs in the endocytotic vesicle. To test these alternative hypotheses for HIV entry, researchers labeled the lipids on the HIV membrane with a red fluorescent dye. What would be observed by live-cell fluorescence microscopy if the red fluorescent lipid dye-labeled HIV membrane fuses with the target cell plasma membrane? A) A spot of red fluorescence will remain on the infected cell's plasma membrane, marking the site of membrane fusion and HIV entry. B) The red fluorescent dye-labeled lipids will diffuse in the infected cell's plasma membrane and become difficult to detect. C) A spot of red fluorescence will move into the infected cell's cytoplasm. D) A spot of red fluorescence will remain outside the cell after delivering the viral capsid. E) Fluorescence microscopy does not have enough resolution to visualize fluorescently labeled HIV virus particles.
Answer: B
66 card image Which functional group is not present in this molecule? A) carboxyl B) sulfhydryl C) hydroxyl D) amino
Answer: B
67 A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism A) is more closely related to humans than to frogs. B) is more closely related to frogs than to humans. C) evolved at about the same time as frogs, which is much earlier than primates and mammals. D) is more closely related to humans than to rats. E) is more closely related to frogs than to humans and also evolved at about the same time as frogs, which is much earlier than primates and mammals.
Answer: B
67 When skeletal muscle cells are oxygen-deprived, the heart still pumps. What must the heart muscle cells be able to do? A) derive sufficient energy from fermentation B) continue aerobic metabolism when skeletal muscle cannot C) transform lactate to pyruvate again D) remove lactate from the blood E) remove oxygen from lactate
Answer: B
67 card image 67) The structure diagrammed in the figure is the A) neuromast. B) statocyst. C) taste bud. D) ommatidium. E) olfactory bulb.
Answer: B
68 The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the female teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. 68) What might be among the research team's conclusions? A) The young women showed these results because they have poorer nutrition. B) The elderly persons' samples demonstrated their lowered immune responses. C) The young men had higher responses because they are generally healthier. D) The patient samples should have had the lowest response but did not, so the experiment is invalid. E) The elderly donor samples represent cells no longer capable of any cell division.
Answer: B
68 When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by A) buildup of pyruvate. B) buildup of lactate. C) increase in sodium ions. D) increase in potassium ions. E) increase in ethanol.
Answer: B
68 card image Referring to Figure 10.3, oxygen would inhibit the CO₂ fixation reactions in A) cell I only. B) cell II only. C) neither cell I nor cell II. D) both cell I and cell II. E) cell I during the night and cell II during the day.
Answer: B
68 card image Using live-cell fluorescence microscopy, researchers observed that a red fluorescent spot moved from the plasma membrane into the interior of target cells when red fluorescent dye-labeled HIV was added to the cells. What is the best conclusion from these observations? A) The hypothesis that HIV enters the cell via fusion with the target cell plasma membrane is proved. B) The hypothesis that HIV enters the cell via fusion with the target cell plasma membrane is not supported. C) The hypothesis that HIV enters the cell via endocytosis is proved. D) The hypothesis that HIV enters the cell via endocytosis is not supported. E) Neither hypothesis is supported by these results.
Answer: B
69 A gardener is concerned that her greenhouse is getting too hot from too much light, and seeks to shade her plants with colored translucent plastic sheets. What color should she use to reduce overall light energy, but still maximize plant growth? A) green B) blue C) yellow D) orange E) any color will work equally well
Answer: B
7 7) To recycle nutrients, an ecosystem must have, at a minimum, A) producers. B) producers and decomposers. C) producers, primary consumers, and decomposers. D) producers, primary consumers, secondary consumers, and decomposers. E) producers, primary consumers, secondary consumers, top carnivores, and decomposers.
Answer: B
7 7) Which of the following terms includes all of the others? A) species diversity B) biodiversity C) genetic diversity D) ecosystem diversity E) species richness
Answer: B
7 In which of the following ways do plant hormones differ from hormones in animals? A) Plant hormones interact primarily with intracellular receptors. B) Plant hormones may travel in air or through vascular systems. C) Animal hormones are found in much greater concentration. D) Plant hormones are synthesized from two or more distinct molecules. E) Animal hormones are primarily for mating and embryonic development.
Answer: B
7 Which of the following takes place as an ice cube cools a drink? A) Molecular collisions in the drink increase. B) Kinetic energy in the drink decreases. C) A calorie of heat energy is transferred from the ice to the water of the drink. D) The specific heat of the water in the drink decreases. E) Evaporation of the water in the drink increases.
Answer: B
70 70) Population ecologists follow the fate of same-age cohorts to A) determine a population's carrying capacity. B) determine the birth rate and death rate of each group in a population. C) determine if a population is regulated by density-dependent processes. D) determine the factors that regulate the size of a population. E) determine if a population's growth is cyclic.
Answer: B
70 card image 70) On the diagram of the nitrogen cycle, which number represents nitrifying bacteria? A) 5 B) 6 C) 7
Answer: B
70 card image Identify the asymmetric carbon in this molecule. A) A B) B C) C D) D E) E
Answer: B
70 card image In an HIV-infected cell producing HIV virus particles, the viral glycoprotein is expressed on the plasma membrane. How do the viral glycoproteins get to the plasma membrane? A) They are synthesized on ribosomes on the plasma membrane. B) They are synthesized by ribosomes in the rough ER, and arrive at the plasma membrane in the membrane of secretory vesicles. C) They are synthesized on free cytoplasmic ribosomes, and then inserted into the plasma membrane. D) They are synthesized by ribosomes in the rough ER, secreted from the cell, and inserted into the plasma membrane from the outside. E) They are synthesized by ribosomes on the HIV viral membrane, which fuses with the plasma membrane from inside the cell.
Answer: B
72 72) Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely A) an animal cell in the process of cytokinesis. B) a plant cell in the process of cytokinesis. C) an animal cell in the S phase of the cell cycle. D) a bacterial cell dividing. E) a plant cell in metaphase.
Answer: B
72 If the sodium ion concentration outside the cell increases, and the CFTR channel is open, in what direction will chloride ions and water move across the cell membrane? A) Chloride ions will move out of the cell, and water will move into the cell. B) Both chloride ions and water will move out of the cell. C) Chloride ions will move into the cell, and water will move out of the cell. D) Both chloride ions and water will move into the cell. E) The movement of chloride ions and water molecules will not be affected by changes in sodium ion concentration outside the cell.
Answer: B
72 Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. If you ran the same experiment without passing light through a prism, what would you predict? A) There would be no difference in results. B) The bacteria would be relatively evenly distributed along the algal filaments. C) The number of bacteria present would decrease due to an increase in the carbon dioxide concentration. D) The number of bacteria present would increase due to an increase in the carbon dioxide concentration. E) The number of bacteria would decrease due to a decrease in the temperature of the water.
Answer: B
73 73) A porcupine eats 3,000 J of plant material. Of this, 2,100 J is indigestible and is eliminated as feces, 800 J are used in cellular respiration, and 100 J are used for growth and reproduction. What is the approximate production efficiency of this animal? A) 0.03% B) 3% C) 10% D) 27% E) 33%
Answer: B
73 card image 73) The structure pictured in the figure is found in A) skeletal muscles and smooth muscles. B) cardiac muscles and skeletal muscles. C) smooth muscles and cardiac muscles. D) smooth muscles, skeletal muscles, and cardiac muscles. E) smooth muscles.
Answer: B
74 74) Keystone predators can maintain species diversity in a community if they A) competitively exclude other predators. B) prey on the community's dominant species. C) allow immigration of other predators. D) reduce the number of disruptions in the community. E) prey only on the least abundant species in the community.
Answer: B
74 A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as A) a coenzyme. B) an allosteric inhibitor. C) the substrate. D) an intermediate. E) a competitive inhibitor.
Answer: B
74 Which structure is not part of the endomembrane system? A) nuclear envelope B) chloroplast C) Golgi apparatus D) plasma membrane E) ER
Answer: B
75 75) Which of these ecosystems has the lowest net primary production per square meter? A) a salt marsh B) an open ocean C) a coral reef D) a grassland E) a tropical rain forest
Answer: B
75 card image 75) Overlapping actin and myosin filaments are found in which section of the figure? A) A B) B C) C D) D E) E
Answer: B
76 In what way do the membranes of a eukaryotic cell vary? A) Phospholipids are found only in certain membranes. B) Certain proteins are unique to each membrane. C) Only certain membranes of the cell are selectively permeable. D) Only certain membranes are constructed from amphipathic molecules. E) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.
Answer: B
76 Which of the following is present in a prokaryotic cell? A) mitochondrion B) ribosome C) nuclear envelope D) chloroplast E) ER
Answer: B
76 Which of the following sequences correctly represents the flow of electrons during photosynthesis? A) NADPH → O₂ → CO₂ B) H₂O → NADPH → Calvin cycle C) NADPH → chlorophyll → Calvin cycle D) H₂O → photosystem I → photosystem II E) NADPH → electron transport chain → O₂
Answer: B
77 77) The most plausible hypothesis to explain why species richness is higher in tropical than in temperate regions is that A) tropical communities are younger. B) tropical regions generally have more available water and higher levels of solar radiation. C) higher temperatures cause more rapid speciation. D) diversity increases as evapotranspiration decreases. E) tropical regions have very high rates of immigration and very low rates of extinction.
Answer: B
77 77) Which of the following does not occur during mitosis? A) condensation of the chromosomes B) replication of the DNA C) separation of sister chromatids D) spindle formation E) separation of the spindle poles
Answer: B
77 Which of the following metabolic processes can occur without a net influx of energy from some other process? A) ADP + Pi → ATP + H₂O B) C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O C) 6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂ D) amino acids → protein E) glucose + fructose → sucrose
Answer: B
78 78) During exponential growth, a population always A) grows by thousands of individuals. B) grows at its maximum per capita rate. C) quickly reaches its carrying capacity. D) cycles through time. E) loses some individuals to emigration.
Answer: B
78 High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of A) competitive inhibition. B) allosteric regulation. C) the specificity of enzymes for their substrates. D) an enzyme requiring a cofactor. E) positive feedback regulation.
Answer: B
78 The reactivity of an atom arises from A) the average distance of the outermost electron shell from the nucleus. B) the existence of unpaired electrons in the valence shell. C) the sum of the potential energies of all the electron shells. D) the potential energy of the valence shell. E) the energy difference between the s and p orbitals.
Answer: B
79 During intense exercise, as skeletal muscle cells go into anaerobiosis, the human body will increase its catabolism of A) fats only. B) carbohydrates only. C) proteins only. D) fats, carbohydrates, and proteins. E) fats and proteins only.
Answer: B
8 8) What type of signal is fast and requires daylight with no obstructions? A) olfactory B) visual C) auditory D) tactile E) electrical
Answer: B
8 A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment? A) red and yellow B) blue and violet C) green and yellow D) blue, green, and red E) green, blue, and yellow
Answer: B
8 Stanley Miller's 1953 experiments assumed that early Earth's atmosphere contained A) hydrogen cyanide, formaldehyde, hydrogen gas, and water vapor. B) ammonia, methane, hydrogen gas, and water vapor. C) ammonia, methane, oxygen gas, and water vapor. D) amino acids, methane, hydrogen cyanide, and water vapor. E) methane, formaldehyde, ammonia, and carbon dioxide.
Answer: B
80 In mechanism, photophosphorylation is most similar to A) substrate-level phosphorylation in glycolysis. B) oxidative phosphorylation in cellular respiration. C) the Calvin cycle. D) carbon fixation. E) reduction of NADP⁺.
Answer: B
80 card image Based on the figure above, which of these experimental treatments would increase the rate of sucrose transport into the cell? A) decreasing extracellular sucrose concentration B) decreasing extracellular pH C) decreasing cytoplasmic pH D) adding an inhibitor that blocks the regeneration of ATP E) adding a substance that makes the membrane more permeable to hydrogen ions
Answer: B
81 81) The transduction of sound waves into action potentials takes place A) within the tectorial membrane as it is stimulated by the hair cells. B) when hair cells are bent against the tectorial membrane, causing them to depolarize and release neurotransmitter that stimulates sensory neurons. C) as the basilar membrane becomes more permeable to sodium ions and depolarizes, initiating an action potential in a sensory neuron. D) as the basilar membrane vibrates at different frequencies in response to the varying volume of sounds. E) within the middle ear as the vibrations are amplified by the malleus, incus, and stapes.
Answer: B
84 card image Which molecule has both hydrophilic and hydrophobic properties and would be found in plasma membranes? A) 1 B) 5 C) 6 D) 12 E) 14
Answer: B
88 card image For each mole of glucose (C₆H₁₂O₆) oxidized by cellular respiration, how many moles of CO₂ are released in the citric acid cycle (see Figure 9.2)? A) 2 B) 4 C) 6 D) 12 E) 3
Answer: B
9 9) Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? A) centromere B) centrosome C) centriole D) chromatid E) kinetochore
Answer: B
9 9) Which statement describes how climate might change if Earth was 75% land and 25% water? A) Terrestrial ecosystems would likely experience more precipitation. B) Earth's daytime temperatures would be higher and nighttime temperatures lower. C) Summers would be longer and winters shorter at midlatitude locations. D) Earth would experience an unprecedented global warming. E) More terrestrial microclimates would be created because of daily fluctuations in climate.
Answer: B
90 [SEE IMAGE FOR CARD #84] Which of the following molecules act as building blocks (monomers) of polypeptides? A) 1, 4, and 6 B) 2, 7, and 8 C) 7, 8, and 13 D) 11, 12, and 13 E) 12, 13, and 15
Answer: B
91 [SEE IMAGE FOR CARD #84] of the following molecules is an amino acid with a hydrophobic R group or side chain? A) 3 B) 7 C) 8 D) 12 E) 13
Answer: B
93 [SEE IMAGE FOR CARD #84] A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between A) one molecule of 9 and three molecules of 10. B) three molecules of 9 and one molecule of 10. C) one molecule of 5 and three molecules of 9. D) three molecules of 5 and one molecule of 9. E) one molecule of 5 and three molecules of 10.
Answer: B
93 card image Which of the following most accurately describes what is happening along the electron transport chain in Figure 9.3? A) Chemiosmosis is coupled with electron transfer. B) Each electron carrier alternates between being reduced and being oxidized. C) ATP is generated at each step. D) Energy of the electrons increases at each step. E) Molecules in the chain give up some of their potential energy.
Answer: B
98 [SEE IMAGE FOR CARD #84] Which of the following molecules consists of a hydrophilic "head" region and a hydrophobic "tail" region? A) 2 B) 5 C) 7 D) 9 E) 11
Answer: B
C₄ plants will have slower growth. E) Plant growth will not be affected because atmospheric CO₂ concentrations are never limiting for plant growth.
Answer: B
What is the term for metabolic pathways that release stored energy by breaking down complex molecules? A) anabolic pathways B) catabolic pathways C) fermentation pathways D) thermodynamic pathways E) bioenergetic pathways
Answer: B
chromosomes moving to the middle of the cell in pairs 41) Which of the steps takes place in both mitosis and meiosis? A) 2 B) 3 C) 5 D) 2 and 3 only E) 2, 3, and 5
Answer: B
enthalpy
Answer: B
58 card image Please read the paragraph below and review Figure 53.2 to answer the following question. Researchers in the Netherlands studied the effects of parental care given in European kestrels over five years. The researchers transferred chicks among nests to produce reduced broods (three or four chicks), normal broods (five or six chicks), and enlarged broods (seven or eight chicks). They then measured the percentage of male and female parent birds that survived the following winter. (Both males and females provide care for chicks.) Figure 53.2: Brood size manipulations in the kestrel: Effects on offspring and parent survival. 58) Which of the following is a conclusion that can be drawn from this graph? A) Female survivability is more negatively affected by larger brood size than is male survivability. B) Male survivability decreased by 50% between reduced and enlarged brood treatments. C) Both males and females had increases in daily hunting with the enlarged brood size. D) There appears to be a negative correlation between brood enlargements and parental survival. E) Chicks in reduced brood treatment received more food, weight gain, and reduced mortality.
Answer: D
68 68) If the DNA content of a diploid cell in the G₁ phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be A) 0.25x. B) 0.5x. C) x. D) 2x. E) 4x.
Answer: D
hydrolysis reactions release hydroxyl groups from polymers. Answer: A 10 Which of the following polymers contain nitrogen? A) starch B) glycogen C) cellulose D) chitin E) amylopectin Answer: D 11 The molecular formula for glucose is C₆H₁2O₆. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? A) C₁₈H₃₆O₁₈ B) C₁₈H₃₂O₁₆ C) C₆H₁₀O₅ D) C1₈H₁₀O₁₅ E) C₃H₆O₃ Answer: B 12 The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down? A) glycogen B) cellulose C) chitin D) glycogen and chitin only E) glycogen, cellulose, and chitin Answer: A 13 On food packages, to what does the term insoluble fiber refer? A) cellulose B) polypeptides C) starch D) amylopectin E) chitin Answer: A 14 A molecule with the chemical formula C₆H₁₂O₆ is probably a A) carbohydrate. B) lipid. C) monosaccharide D) carbohydrate and lipid only. E) carbohydrate and monosaccharide only. Answer: E 15 Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? A) as a pentose B) as a hexose C) as a monosaccharide D) as a disaccharide E) as a polysaccharide Answer: D 16 All of the following are polysaccharides except A) lactose. B) glycogen. C) chitin. D) cellulose. E) amylopectin. Answer: A 17 of the following is true of both starch and cellulose? A) They are both polymers of glucose. B) They are cis-trans isomers of each other. C) They can both be digested by humans. D) They are both used for energy storage in plants. E) They are both structural components of the plant cell wall. Answer: A 18 Which of the following is true of cellulose? A) It is a polymer composed of enantiomers of glucose. B) It is a storage polysaccharide for energy in plant cells. C) It is digestible by bacteria in the human gut. D) It is a major structural component of plant cell walls. E) It is a polymer composed of enantiomers of glucose, it is a storage polysaccharide for energy in plant cells, it is digestible by bacteria in the human gut, and it is a major structural component of plant cell walls. Answer: D 19 Humans can digest starch but not cellulose because A) the monomer of starch is glucose, while the monomer of cellulose is galactose. B) humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose. C) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose. D) humans harbor starch-digesting bacteria in the digestive tract. E) the monomer of starch is glucose, while the monomer of cellulose is glucose with a nitrogen-containing group. Answer: C 20 Which of the following statements concerning saturated fats is not true? A) They are more common in animals than in plants. B) They have multiple double bonds in the carbon chains of their fatty acids. C) They generally solidify at room temperature. D) They contain more hydrogen than unsaturated fats having the same number of carbon atoms. E) They are one of several factors that contribute to atherosclerosis. Answer: B 21 A molecule with the formula C₁₈H3₆O₂ is probably a A) carbohydrate. B) fatty acid. C) protein. D) nucleic acid. E) hydrocarbon.
Answer: B
that is, molecules that A) have identical chemical formulas but differ in the branching of their carbon skeletons. B) are mirror images of one another. C) exist in either linear chain or ring forms. D) differ in the location of their double bonds. E) differ in the arrangement of atoms around their double bonds.
Answer: B
1 In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by A) hydrogen bonds. B) nonpolar covalent bonds. C) polar covalent bonds. D) ionic bonds. E) van der Waals interactions.
Answer: C
1) A female cat in heat urinates more often and in many places. Male cats are attracted to the urine deposits. Which of the following is a proximate cause of this increased urination? A) It announces to the males that she is in heat. B) Female cats that did this in the past attracted more males. C) It is a result of hormonal changes associated with her reproductive cycle. D) The female cat learned the behavior from observing other cats. E) All of the options are ultimate causes of behavior.
Answer: C
1) If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? A) Backtrack through her previous experiments to obtain another plant with the same traits. B) Breed this plant with another plant with much weaker traits. C) Clone the plant asexually to produce an identical one. D) Force the plant to self-pollinate to obtain an identical one. E) Add nitrogen to the soil of the offspring of this plant so the desired traits continue.
Answer: C
10 10) A given photon of light may trigger an action potential with thousands of times more energy because the signal strength is magnified by A) the receptor. B) a G protein. C) an enzyme-catalyzed reaction. D) sensory adaptation. E) triggering several receptors at once.
Answer: C
10 10) Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 km from where they are born and become 1%-8% of the males and 0.7%-6% of the females in other populations. On an evolutionary scale, why is this significant? A) These immigrants make up for the deaths of individuals, keeping the other populations' size stable. B) Young reproductive males tend to stay in their home population and are not driven out by other territorial males. C) These immigrants provide a source of genetic diversity for the other populations. D) Those individuals that emigrate to these new populations are looking for less crowded conditions with more resources. E) Gradually, the populations of ground squirrels will move from a clumped to a uniform population pattern of dispersion.
Answer: C
10 10) Which of the following abiotic factors has the greatest influence on the metabolic rates of plants and animals? A) water B) wind C) temperature D) rocks and soil E) disturbances
Answer: C
10 Liquid water's high specific heat is mainly a consequence of the A) small size of the water molecules. B) high specific heat of oxygen and hydrogen atoms. C) absorption and release of heat when hydrogen bonds break and form. D) fact that water is a poor heat conductor. E) higher density of liquid water than solid water (ice).
Answer: C
10 The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal cells. The most reasonable explanation for this observation is that A) plant cells are capable of having a much higher surface-to-volume ratio than animal cells. B) plant cells have a much more highly convoluted (folded) plasma membrane than animal cells. C) plant cells contain a large vacuole that reduces the volume of the cytoplasm. D) animal cells are more spherical, whereas plant cells are elongated. E) plant cells can have lower surface-to-volume ratios than animal cells because plant cells synthesize their own nutrients.
Answer: C
100 Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each synthesized from four nucleotides. Among these biological polymers, which has the least structural variety? A) polysaccharides B) proteins C) DNA D) RNA
Answer: C
102 Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule? A) the citric acid cycle B) the electron transport chain C) glycolysis D) synthesis of acetyl CoA from pyruvate E) reduction of pyruvate to lactate
Answer: C
103 In mitochondria, exergonic redox reactions A) are the source of energy driving prokaryotic ATP synthesis. B) are directly coupled to substrate-level phosphorylation. C) provide the energy that establishes the proton gradient. D) reduce carbon atoms to carbon dioxide. E) are coupled via phosphorylated intermediates to endergonic processes.
Answer: C
108 The molecular formula for glucose is C₆H₁₂O₆. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A) C₆₀H₁₂₀O₆₀ B) C₆H₁₂O₆ C) C₆₀H₁₀₂O₅₁ D) C₆₀H₁₀₀O₅₀ E) C₆₀H₁₁₁O₅₁
Answer: C
11 11) Circannual rhythms in birds are influenced by A) periods of food availability. B) reproductive readiness. C) periods of daylight and darkness. D) magnetic fields. E) lunar cycles.
Answer: C
11 11) If the sun were to suddenly stop providing energy to Earth, most ecosystems would vanish. Which of the following ecosystems would likely survive the longest after this hypothetical disaster? A) tropical rain forest B) tundra C) benthic ocean D) grassland E) desert
Answer: C
11 11) What term did E. O. Wilson coin for our innate appreciation of wild environments and living organisms? A) bioremediation B) bioethics C) biophilia D) biophobia E) landscape ecology
Answer: C
11 A carbon atom is most likely to form what kind of bond(s) with other atoms? A) ionic B) hydrogen C) covalent D) covalent bonds and hydrogen bonds E) ionic bonds, covalent bonds, and hydrogen bonds
Answer: C
11 Carbon-12 is the most common isotope of carbon, and has an atomic mass of 12 daltons. A mole of carbon in naturally occurring coal, however, weighs slightly more than 12 grams. Why? A) The atomic mass does not include the mass of electrons. B) Some carbon atoms in nature have an extra proton. C) Some carbon atoms in nature have more neutrons. D) Some carbon atoms in nature have a different valence electron distribution. E) Some carbon atoms in nature have undergone radioactive decay.
Answer: C
12 12) Which of the following is true of detrivores? A) They recycle chemical elements directly back to primary consumers. B) They synthesize organic molecules that are used by primary producers. C) They convert organic materials from all trophic levels to inorganic compounds usable by primary producers. D) They secrete enzymes that convert the organic molecules of detritus into CO₂ and H₂O. E) Some species are autotrophic, while others are heterotrophic.
Answer: C
12 Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? A) the change in density when it condenses to form a liquid or solid B) reactions with other atmospheric compounds C) the release of heat by the formation of hydrogen bonds D) the release of heat by the breaking of hydrogen bonds E) the high surface tension of water
Answer: C
12 card image Which of the following best describes the relationship between the atoms described below? [SEE IMAGE] A) They are isomers. B) They are polymers. C) They are isotopes. D) They contain 1 and 3 protons, respectively. E) They each contain 1 neutron.
Answer: C
13 13) Which of the following is the best example of uniform distribution? A) bees collecting pollen in a wildflower meadow B) snails in an intertidal zone at low tide C) territorial songbirds in a mature forest during mating season D) mushrooms growing on the floor of an old growth forest E) a cultivated cornfield in the Midwest
Answer: C
59 59) In a typical grassland community, which of the following is the primary consumer? A) hawk B) snake C) shrew D) grasshopper E) grass
Answer: D
14 The mathematical expression for the change in free energy of a system is ΔG =ΔH - TΔS. Which of the following is (are) correct? A) ΔS is the change in enthalpy, a measure of randomness. B) ΔH is the change in entropy, the energy available to do work. C) ΔG is the change in free energy. D) T is the temperature in degrees Celsius.
Answer: C
15 15) Displays of nocturnal mammals are usually A) visual and auditory. B) tactile and visual. C) olfactory and auditory. D) visual and olfactory. E) tactile and auditory.
Answer: C
15 15) Monarch butterflies are protected from birds and other predators because of cardiac glycosides they incorporate into their tissues from eating milkweed when they were in their caterpillar stage. The wings of a different species of butterfly, the Viceroy, look nearly identical to the Monarch so predators that have learned not to eat the bad-tasting Monarch avoid Viceroys as well. This example best describes A) aposmatic coloration. B) cryptic coloration. C) Batesian mimicry. D) Müllerian mimicry. E) mutualism.
Answer: C
15 What are the products of linear photophosphorylation? A) heat and fluorescence B) ATP and P700 C) ATP and NADPH D) ADP and NADP E) P700 and P680
Answer: C
16 16) A karyotype results from which of the following? A) a natural cellular arrangement of chromosomes in the nucleus B) an inherited ability of chromosomes to arrange themselves C) the ordering of human chromosome images D) the cutting and pasting of parts of chromosomes to form the standard array E) the separation of homologous chromosomes at metaphase I of meiosis
Answer: C
16 16) For anaphase to begin, which of the following must occur? A) Chromatids must lose their kinetochores. B) Cohesin must attach the sister chromatids to each other. C) Cohesin must be cleaved enzymatically. D) Kinetochores must attach to the metaphase plate. E) Spindle microtubules must begin to depolymerize.
Answer: C
16 16) Subtraction of which of the following will convert gross primary productivity into net primary productivity? A) the energy contained in the standing crop B) the energy used by heterotrophs in respiration C) the energy used by autotrophs in respiration D) the energy fixed by photosynthesis E) all solar energy
Answer: C
16 16) Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve? A) Many invertebrates mate and produce offspring on multiyear cycles. B) Within a species of invertebrates, younger individuals have a higher survivorship than older individuals. C) Many invertebrates molt in order to grow, and they are vulnerable to predation during their "soft shell" stage. D) Many invertebrate species have population cycles that go up and down according to the frequency of sunspots. E) The number of fertilized eggs that mature to become females in many species of invertebrates is based on ambient temperature.
Answer: C
16 As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? A) photosystem II B) photosystem I C) cyclic electron flow D) linear electron flow E) chlorophyll
Answer: C
16 During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is A) transferred to ADP, forming ATP. B) transferred directly to ATP. C) retained in the two pyruvates. D) stored in the NADH produced. E) used to phosphorylate fructose to form fructose 6-phosphate.
Answer: C
16 The atomic number of nitrogen is 7. Nitrogen-15 is heavier than nitrogen-14 because the atomic nucleus of nitrogen-15 contains how many neutrons? A) 6 B) 7 C) 8 D) 12 E) 14
Answer: C
17 17) The success with which plants extend their range northward following glacial retreat is best determined by A) whether there is simultaneous migration of herbivores. B) their tolerance to shade. C) their seed dispersal rate. D) their size. E) their growth rate.
Answer: C
17 17) Which statement best describes the evolutionary significance of mutualism? A) Mutualism offers more biodiversity to a community. B) Individuals partaking in a mutualistic relationship are more resistant to parasites. C) Interaction increases the survival and reproductive rates of mutualistic species. D) Mutualistic interaction lessens competition in communities where it is present. E) Mutualistic relationships allow organisms to synthesize and use energy more efficiently.
Answer: C
17 In addition to ATP, what are the end products of glycolysis? A) CO₂ and H₂O B) CO₂ and pyruvate C) NADH and pyruvate D) CO₂ and NADH E) H₂O, FADH₂, and citrate
Answer: C
17 Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question. A. operant conditioning B. agonistic behavior C. innate behavior D. imprinting E. altruistic behavior 17) A human baby performs a sucking behavior perfectly when it is put in the presence of the nipple of its mother's breast. A) A B) B C) C D) D E) E
Answer: C
17 Receptor tyrosine kinases (RTKs) are found at high levels on various cancer cells. A protein, Herceptin, has been found to bind to an RTK known as HER2. This information can now be utilized in breast cancer treatment if which of the following is true? A) If Herceptin is found in the breast lymph nodes of the patient. B) If HER2, administered by injection, is in sufficient concentration. C) If the patient's cancer cells have detectable HER2. D) If the patient's genome codes for the HER2 receptor. E) If the patient's genome codes for the manufacture of Herceptin.
Answer: C
18 Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? A) lipids B) glycogen C) proteins D) cellulose E) nucleic acids
Answer: C
18 The cell membranes of Antarctic ice fish might have which of the following adaptations? A) very long chain fatty acids B) branched isoprenoid lipids C) a high percentage of polyunsaturated fatty acids D) a higher percentage of trans-fatty acids E) no cholesterol
Answer: C
18 Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein? A) +ΔH, +ΔS, +ΔG B) +ΔH, -ΔS, -ΔG C) +ΔH, -ΔS, +ΔG D) -ΔH, -ΔS, +ΔG E) -ΔH, +ΔS, +ΔG
Answer: C
19 19) The perceived pitch of a sound depends on A) which part of the tympanic membrane is being vibrated by sound waves. B) which part of the oval window produces waves in the cochlear fluid. C) which region of the basilar membrane was set in motion. D) whether or not the sound moves the incus, malleus, and stapes. E) the listener having had training in music.
Answer: C
19 In a paramecium, cell surface integral membrane proteins are synthesized A) in the cytoplasm by free ribosomes. B) by ribosomes in the nucleus. C) by ribosomes bound to the rough endoplasmic reticulum. D) by ribosomes in the Golgi vesicles. E) by ribosomes bound to the inner surface of the plasma membrane.
Answer: C
19 The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? A) the loss of all nuclear function B) the inability of the nucleus to divide during cell division C) a change in the shape of the nucleus D) failure of chromosomes to carry genetic information E) inability of the nucleus to keep out destructive chemicals
Answer: C
19 When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na⁺) and chloride ions (Cl⁻). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)? A) 1 L of 0.5 M NaCl B) 1 L of 0.5 M glucose C) 1 L of 1.0 M NaCl D) 1 L of 1.0 M glucose E) 1 L of 1.0 M NaCl and 1 L of 1.0 M glucose will contain equal numbers of solute particles.
Answer: C
2 2) A female cat in heat urinates more often and in many places. Male cats congregate near the urine deposits and fight with each other. Which of the following would be an ultimate cause of the male cats' response to the female's urinating behavior? A) The males have learned to recognize the specific odor of the urine of a female in heat. B) When the males smelled the odor, various neurons in their brains were stimulated. C) Responding to the odor means locating reproductively receptive females. D) Male cats' hormones are triggered by the odor released by the female. E) The odor serves as a releaser for the instinctive behavior of the males.
Answer: C
2 2) A population is correctly defined as having which of the following characteristics? I. inhabiting the same general area II. belonging to the same species III. possessing a constant and uniform density and dispersion A) I only B) III only C) I and II only D) II and III only E) I, II, and III
Answer: C
2 Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into A) the energy of motion B) carbon dioxide and water C) the potential energy of chemical bonds D) oxygen E) kinetic energy
Answer: C
2 The advantage of light microscopy over electron microscopy is that A) light microscopy provides for higher magnification than electron microscopy. B) light microscopy provides for higher resolving power than electron microscopy. C) light microscopy allows one to view dynamic processes in living cells. D) light microscopy provides higher contrast than electron microscopy. E) specimen preparation for light microcopy does not produce artifacts.
Answer: C
2 Which of the following is (are) true for anabolic pathways? A) They do not depend on enzymes. B) They are usually highly spontaneous chemical reactions. C) They consume energy to build up polymers from monomers. D) They release energy as they degrade polymers to monomers. E) They consume energy to decrease the entropy of the organism and its environment.
Answer: C
21 21) How did Eugene Odum describe an ecological niche? A) the "address" of an organism B) an entity that is synonymous with an organism's specific trophic level C) an organism's "profession" in the community D) the organism's role in recycling nutrients in its habitat E) the interactions of the organism with other members of the community
Answer: C
21 21) If mayflies lay eggs on roads instead of in water, it would indicate which of the following? A) a defective gene B) trial-and-error learning C) a misdirected response to a sign stimulus D) a natural behavioral variation in the mayfly population E) aberrant behavior due to insecticide poisoning
Answer: C
21 21) The somatic cells of a privet shrub each contain 46 chromosomes. To be as different as they are from human cells, which have the same number of chromosomes, which of the following must be true? A) Privet cells cannot reproduce sexually. B) Privet sex cells have chromosomes that can synapse with human chromosomes in the laboratory. C) Genes of privet chromosomes are significantly different than those in humans. D) Privet shrubs must be metabolically more like animals than like other shrubs. E) Genes on a particular privet chromosome, such as the X, must be on a different human chromosome, such as number 18.
Answer: C
21 Cell membranes are asymmetrical. Which of the following is the most likely explanation? A) The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium. B) Cell membranes communicate signals from one organism to another. C) The two sides of a cell membrane face different environments and carry out different functions. D) The "innerness" and "outerness" of membrane surfaces are predetermined by genes. E) Proteins can only be associated with the cell membranes on the cytoplasmic side.
Answer: C
21 In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from A) the stroma to the photosystem II. B) the matrix to the stroma. C) the stroma to the thylakoid space. D) the intermembrane space to the matrix. E) the thylakoid space to the stroma.
Answer: C
21 Which of the following best describes what occurred after the publication of Charles Darwin's On the Origin of Species? A) The book received little attention except from a small scientific community. B) The book was banned from schools. C) The book was widely discussed and disseminated. D) The book's authorship was disputed. E) The book was discredited by most scientists.
Answer: C
21 Which of the following is the best explanation for the inability of a specific animal cell to reduce the Ca2⁺ concentration in its cytosol compared with the extracellular fluid? A) blockage of the synaptic signal B) loss of transcription factors C) insufficient ATP levels in the cytoplasm D) low oxygen concentration around the cell E) low levels of protein kinase in the cell
Answer: C
22 22) How is it that the open ocean produces the highest net primary productivity of Earth's ecosystems, yet net primary productivity per square meter is relatively low? A) Oceans contain greater concentrations of nutrients compared to other ecosystems. B) Oceans receive a lesser amount of solar energy per unit area. C) Oceans have the largest area of all the ecosystems on Earth. D) Ocean ecosystems have less species diversity. E) Oceanic producers are generally much smaller than oceanic consumers.
Answer: C
22 22) In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common? A) Length and position of the centromere only. B) Length, centromere position, and staining pattern only. C) Length, centromere position, staining pattern, and traits coded for by their genes. D) Length, centromere position, staining pattern, and DNA sequences. E) They have nothing in common except they are X-shaped.
Answer: C
22 22) Which of the following are important biotic factors that can affect the structure and organization of biological communities? A) precipitation, wind B) nutrient availability, soil pH C) predation, competition D) temperature, water E) light intensity, seasonality
Answer: C
22 Which kind of metabolic poison would most directly interfere with glycolysis? A) an agent that reacts with oxygen and depletes its concentration in the cell B) an agent that binds to pyruvate and inactivates it C) an agent that closely mimics the structure of glucose but is not metabolized D) an agent that reacts with NADH and oxidizes it to NAD⁺ E) an agent that blocks the passage of electrons along the electron transport chain
Answer: C
22 Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids? A) ribosome B) lysosome C) smooth endoplasmic reticulum D) mitochondrion E) contractile vacuole
Answer: C
23 23) In 2008, the population of New Zealand was approximately 4,275,000 people. If the birth rate was 14 births for every 1,000 people, approximately how many births occurred in New Zealand in 2008? A) 6,000 B) 42,275 C) 60,000 D) 140,000 E) 600,000
Answer: C
23 23) What is a cleavage furrow? A) a ring of vesicles forming a cell plate B) the separation of divided prokaryotes C) a groove in the plasma membrane between daughter nuclei D) the metaphase plate where chromosomes attach to the spindle E) the space that is created between two chromatids during anaphase
Answer: C
23 Darwin's finches, collected from the Galápagos Islands, illustrate which of the following? A) mutation frequency B) ancestors from different regions C) adaptive radiation D) vestigial anatomic structures E) the accuracy of the fossil record
Answer: C
23 Which two functional groups are always found in amino acids? A) ketone and methyl B) carbonyl and amino C) carboxyl and amino D) amino and sulfhydryl E) hydroxyl and carboxyl
Answer: C
24 24) Consider two forests: one is an undisturbed old-growth forest, while the other has recently been logged. In which forest are species likely to experience exponential growth, and why? A) Old growth, because of stable conditions that would favor exponential growth of all species in the forest. B) Old growth, because each of the species is well established and can produce many offspring. C) Logged, because the disturbed forest affords more resources for increased specific populations to grow. D) Logged, because the various populations are stimulated to a higher reproductive potential. E) Exponential growth is equally probable in old-growth and logged forests.
Answer: C
24 24) How is net ecosystem production (NEP) typically estimated in ecosystems? A) the ratio of producers to consumers B) the amount of heat energy released by the ecosystem C) the net flux of CO₂ or O₂ in or out of an ecosystem D) the rate of decomposition by detrivores E) the annual total of incoming solar radiation per unit of area
Answer: C
24 24) Learning in which an associated stimulus may be used to elicit the same behavioral response as the original sign stimulus is called A) concept formation. B) trial and error. C) classical conditioning. D) operant conditioning. E) cognition.
Answer: C
24 In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during A) photosynthesis only. B) respiration only. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration only.
Answer: C
24 Which of the following is true regarding saturated fatty acids? A) They are the predominant fatty acid in corn oil. B) They have double bonds between carbon atoms of the fatty acids. C) They are the principal molecules in lard and butter. D) They are usually liquid at room temperature. E) They are usually produced by plants.
Answer: C
25 25) Every morning at the same time, John went into the den to feed his new tropical fish. After a few weeks, he noticed that the fish swam to the top of the tank when he entered the room. This is an example of A) cognition. B) imprinting. C) classical conditioning. D) operant conditioning. E) maturation.
Answer: C
25 Which of the following is most similar in structure to ATP? A) a pentose sugar B) a DNA nucleotide C) an RNA nucleotide D) an amino acid with three phosphate groups attached E) a phospholipid
Answer: C
26 26) According to the small-population approach, what would be the best strategy for saving a population that is in an extinction vortex? A) determining the minimum viable population size by taking into account the effective population size B) establishing a nature reserve to protect its habitat C) introducing individuals from other populations to increase genetic variation D) determining and remedying the cause of its decline E) reducing the population size of its predators and competitors
Answer: C
26 26) Most of the chemosensory neurons arising in the nasal cavity have axonal projections that terminate in the A) gustatory complex. B) anterior hypothalamus. C) olfactory bulb. D) occipital lobe. E) posterior pituitary gland.
Answer: C
26 Adenylyl cyclase has the opposite effect of which of the following? A) protein kinase B) protein phosphatase C) phosphodiesterase D) phosphorylase E) GTPase
Answer: C
26 The difference in lipid and protein composition between the membranes of the endomembrane system is largely determined by A) the physical separation of most membranes from each other. B) the transportation of membrane lipids among the endomembrane system by small membrane vesicles. C) the function of the Golgi apparatus in sorting and directing membrane components. D) the modification of the membrane components once they reach their final destination. E) the synthesis of different lipids and proteins in each of the organelles of the endomembrane system.
Answer: C
26 Which functional groups can act as acids? A) amino and sulfhydryl B) carbonyl and carboxyl C) carboxyl and phosphate D) hydroxyl and aldehyde E) ketone and amino
Answer: C
27 27) A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G₂? A) The cells would immediately die. B) The cells would be unable to begin M and stay in G₂. C) The chromosomes would coil and shorten but have no spindle to which to attach. D) The chromosomes would segregate but in a disorderly pattern. E) Each resultant daughter cell would also be unable to form a spindle.
Answer: C
27 Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of A) phosphorylated proteins. B) GTP. C) cAMP. D) adenylyl cyclase. E) activated G proteins.
Answer: C
28 A given solution contains 0.0001(10⁻⁴) moles of hydrogen ions [H⁺] per liter. Which of the following best describes this solution? A) acidic: will accept H⁺ from both strong and weak acids B) basic: will accept H⁺ from both strong and weak acids C) acidic: will give H⁺ to weak acids, but accept H+ from strong acids D) basic: will give H⁺ to weak acids, but accept H⁺ from weak acids E) acidic: will give H⁺ to both strong and weak acids
Answer: C
28 Generation of proton gradients across membranes occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration.
Answer: C
28 If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound A) that activates epinephrine receptors. B) that increases cAMP production in liver cells. C) to block G protein activity in liver cells. D) that increases phosphorylase activity. E) that keeps sugar molecules from crossing the plasma membrane of liver cells.
Answer: C
28 Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? A) Testosterone and estradiol are structural isomers but have the same molecular formula. B) Testosterone and estradiol are cis-trans isomers but have the same molecular formula. C) Testosterone and estradiol have different functional groups attached to the same carbon skeleton. D) Testosterone and estradiol have distinctly different chemical structures, with one including four fused rings of carbon atoms, while the other has three rings. E) Testosterone and estradiol are enantiomers of the same organic molecule.
Answer: C
28 Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells? A) Prokaryotes are unlikely to be able to secrete proteins because they lack an endomembrane system. B) The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes. C) Proteins that are secreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane. D) In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside of the cell. E) Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell.
Answer: C
28 Which of the following statements is correct about diffusion? A) It is very rapid over long distances. B) It requires an expenditure of energy by the cell. C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. D) It is an active process in which molecules move from a region of lower concentration to one of higher concentration. E) It requires integral proteins in the cell membrane.
Answer: C
29 A covalent chemical bond is one in which A) electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged. B) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms. C) outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms. D) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom. E) an electron occupies a hybrid orbital located between the nuclei of two atoms.
Answer: C
29 A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a resting muscle cell's cytosol has a free calcium ion concentration of 10⁻⁷ while the concentration in the SR is 10⁻², then how is the ATPase acting? A) ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR. B) ATPase activity must be transferring Pi to the SR to enable this to occur. C) ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. D) ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient. E) ATPase activity must be routing calcium ions from the SR to the cytosol, and then to the cell's environment.
Answer: C
29 Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition? A) the endoplasmic reticulum B) the Golgi apparatus C) the lysosome D) mitochondria E) membrane-bound ribosomes
Answer: C
3 3) Estimates of current rates of extinction A) indicate that we have reached a state of stable equilibrium in which speciation rates equal extinction rates. B) suggest that one-half of all animal and plant species may be gone by the year 2100. C) indicate that rates may be greater than the mass extinctions at the close of the Cretaceous period. D) indicate that only 1% of all of the species that have ever lived on Earth are still alive. E) suggest that rates of extinction have decreased globally.
Answer: C
3 3) Which of the following examples describes a behavioral pattern that results from a proximate cause? A) A cat kills a mouse to obtain nutrition. B) A male sheep fights with another male because it helps to improve its social position. C) A female bird lays its eggs because the amount of daylight is decreasing slightly each day. D) A goose squats and freezes motionless to escape a predator. E) A cockroach runs into a crack in the wall and avoids being stepped on.
Answer: C
69 69) The oceans affect the biosphere in all of the following ways except A) producing a substantial amount of the biosphere's oxygen. B) removing carbon dioxide from the atmosphere. C) moderating the climate of terrestrial biomes. D) regulating the pH of freshwater biomes and terrestrial groundwater. E) being the source of most of Earth's rainfall.
Answer: D
69 What types of proteins are not synthesized in the rough ER? A) endoplasmic reticulum proteins B) extracellular matrix proteins C) secreted proteins D) mitochondrial proteins E) plasma membrane proteins
Answer: D
7 7) If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested? A) anaphase B) prophase C) telophase D) metaphase E) interphase
Answer: D
7 7) The human X and Y chromosomes A) are both present in every somatic cell of males and females alike. B) are of approximately equal size and number of genes. C) are almost entirely homologous, despite their different names. D) include genes that determine an individual's sex. E) include only genes that govern sex determination.
Answer: D
7 In what way are elements in the same column of the periodic table the same? A) They have the same number of protons. B) They have the same number of neutrons. C) They have the same number of electrons. D) They have the same number of electrons in their valence shell. E) They have the same number of electron shells.
Answer: D
7 Which of the following statements is a logical consequence of the second law of thermodynamics? A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. B) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. C) Every energy transfer requires activation energy from the environment. D) Every chemical reaction must increase the total entropy of the universe. E) Energy can be transferred or transformed, but it cannot be created or destroyed.
Answer: D
3 3) Which of the following examples of an ecological effect leading to an evolutionary effect is most correct? A) When seeds are not plentiful, trees produce more seeds. B) A few organisms of a larger population survive a drought and then these survivors emigrate to less arid environments. C) A few individuals with denser fur survive the coldest days of an ice age, and the reproducing survivors of the ice age all have long fur. D) Fish that swim the fastest in running water catch the most prey and more easily escape predation. E) The insects that spend the most time exposed to sunlight have the most mutations.
Answer: C
3 Which of the following statements is false? A) Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter. B) Some trace elements are very abundant on Earth. C) Virtually all organisms require the same elements in the same quantities. D) Iron is an example of an element needed by all organisms. E) Other than some trace elements, animals are mostly made up of the same elements as plants, in similar proportions.
Answer: C
30 30) Modern conservation biology increasingly aims at A) protecting federally listed endangered species. B) lobbying for strict enforcement of the U.S. Endangered Species Act. C) sustaining biodiversity of entire ecosystems and communities. D) maintaining genetic diversity in all species. E) saving as much habitat as possible from development and exploitation.
Answer: C
30 30) Why are food chains relatively short? A) Top-level feeders tend to be more numerous than lower-trophic-level species. B) Top-level feeders tend to be small but are capable of conserving more energy. C) Longer chains are less stable and energy transfer between levels is inefficient. D) There are only so many organisms that are adapted to feed on other types of organisms. E) Food chain length is ultimately determined by the photosynthetic efficiency of producers.
Answer: C
30 Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are A) hypotonic to both fresh water and the salt solution. B) hypertonic to both fresh water and the salt solution. C) hypertonic to fresh water but hypotonic to the salt solution. D) hypotonic to fresh water but hypertonic to the salt solution. E) isotonic with fresh water but hypotonic to the salt solution.
Answer: C
30 There are 20 different amino acids. What makes one amino acid different from another? A) different side chains (R groups) attached to a carboxyl carbon B) different side chains (R groups) attached to the amino groups C) different side chains (R groups) attached to an α carbon D) different structural and optical isomers E) different asymmetric carbons
Answer: C
31 31) A 3-hectare lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of eutrophication in freshwater ecosystems, such as this one? A) increased solar radiation B) introduction of non-native tertiary consumer fish C) nutrient runoff D) accidental introduction of a prolific culture of algae E) iron dust blowing into the lake
Answer: C
31 31) Classical conditioning and operant conditioning differ in that A) classical conditioning takes longer. B) operant conditioning usually involves more intelligence. C) operant conditioning involves consequences for the animal's behavior. D) classical conditioning is restricted to mammals and birds. E) classical conditioning is much more useful for training domestic animals.
Answer: C
31 31) Which of the following statements about the evolution of life histories is correct? A) Stable environments with limited resources favor r-selected populations. B) K-selected populations are most often found in environments where density-independent factors are important regulators of population size. C) Most populations have both r- and K-selected characteristics that vary under different environmental conditions. D) The reproductive efforts of r-selected populations are directed at producing just a few offspring with good competitive abilities. E) K-selected populations rarely approach carrying capacity.
Answer: C
32 32) Whether during mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesins. Such molecules must have which of the following properties? A) They must persist throughout the cell cycle. B) They must be removed before meiosis can begin. C) They must be removed before anaphase can occur. D) They must reattach to chromosomes during G₁. E) They must be intact for nuclear envelope reformation.
Answer: C
32 Where are the proteins of the electron transport chain located? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix
Answer: C
32 Which of the following is a correct association? A) kinase activity and the addition of a tyrosine B) phosphodiesterase activity and the removal of phosphate groups C) GTPase activity and hydrolysis of GTP to GDP D) phosphorylase activity and the catabolism of glucose E) adenylyl cyclase activity and the conversion of cAMP to AMP
Answer: C
33 33) Experiments with cohesins have found that A) cohesins are protected from destruction throughout meiosis I and II. B) cohesins are cleaved from chromosomes at the centromere before anaphase I. C) cohesins are protected from cleavage at the centromere during meiosis I. D) a protein cleaves cohesins before metaphase I. E) a protein that cleaves cohesins would cause cellular death.
Answer: C
33 33) The three basic variables that make up the life history of an organism are A) life expectancy, birth rate, and death rate. B) number of reproductive females in the population, age structure of the population, and life expectancy. C) age when reproduction begins, how often reproduction occurs, and how many offspring are produced per reproductive episode. D) how often reproduction occurs, life expectancy of females in the population, and number of offspring per reproductive episode. E) the number of reproductive females in the population, how often reproduction occurs, and death rate.
Answer: C
33 33) What is secondary production? A) energy converted by secondary consumers from primary consumers B) solar energy that is converted to chemical energy by photosynthesis C) food that is converted to new biomass by consumers D) energy that is not used by consumers for growth and reproduction E) growth that takes place during the second year of life in consumers
Answer: C
33 A controlled experiment is one in which A) the experiment is repeated many times to ensure that the results are accurate. B) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. C) there are at least two groups, one of which does not receive the experimental treatment. D) there are at least two groups, one differing from the other by two or more variables. E) there is one group for which the scientist controls all variables.
Answer: C
33 A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because A) the starch solution has less free energy than the sugar solution. B) the hydrolysis of starch to sugar is endergonic. C) the activation energy barrier for this reaction cannot be surmounted. D) starch cannot be hydrolyzed in the presence of so much water. E) starch hydrolysis is nonspontaneous.
Answer: C
34 34) The 1988 Yellowstone National Park lodgepole pine forest fires were likely the result of A) overgrazing by elk. B) infrequent rain episodes. C) years of fire suppression by humans. D) unextinguished campfires. E) geysers.
Answer: C
34 Which of the following is the best explanation for the fact that most transduction pathways have multiple steps? A) Most of the steps were already in place because they are steps in other pathways. B) Multiple steps in a pathway require the least amount of ATP. C) Multiple steps provide for greater possible amplification of a signal. D) Each individual step can remove excess phosphate groups from the cytoplasm. E) Each step can be activated by several G proteins simultaneously.
Answer: C
34 Which organelle is the primary site of ATP synthesis in eukaryotic cells? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome
Answer: C
35 Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction? A) tyrosines B) glycine and histidine C) serine and threonine D) glycine and glutamic acid E) Any of the 20 amino acids are equally phosphorylated.
Answer: C
35 Which of the following membrane activities require energy from ATP hydrolysis? A) facilitated diffusion of chloride ions across the membrane through a chloride channel B) movement of water into a cell C) Na⁺ ions moving out of a mammalian cell bathed in physiological saline D) movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell E) movement of carbon dioxide out of a paramecium
Answer: C
35 Which plant cell organelle contains its own DNA and ribosomes? A) glyoxysome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome
Answer: C
36 36) For the processing of visual information in the central nervous system of humans, the neuronal projections of ganglion cells to the left and right lateral geniculate nuclei (LGN) are A) all ipsilateral, meaning that left eye projections stay on the left side of the brain, and vice versa. B) all contralateral, meaning that left eye projections project to the right side of the brain, and vice versa. C) ipsilateral for the temporal side of each retina, and contralateral for the nasal side of each retina. D) ipsilateral for the nasal side of each retina, and contralateral for the temporal side of each retina. E) randomly crossed in terms of which side of the retina projects to either the left or right side of the brain.
Answer: C
37 37) Relatively small geographic areas with high concentrations of endemic species and a large number of endangered and threatened species are known as A) endemic sinks. B) critical communities. C) biodiversity hot spots. D) endemic metapopulations. E) bottlenecks.
Answer: C
37 During aerobic respiration, H₂O is formed. Where does the oxygen atom for the formation of the water come from? A) carbon dioxide (CO₂) B) glucose (C₆H₁₂O₆) C) molecular oxygen (O₂) D) pyruvate (C₃H₃O₃-) E) lactate (C₃H₅O₃-)
Answer: C
38 38) A certain species of pine tree survives only in scattered locations at elevations above 2,800 m in the western United States. To understand why this tree grows only in these specific places, an ecologist should A) conclude that lower elevations are limiting to the survival of this species. B) study the anatomy and physiology of this species. C) investigate the various biotic and abiotic factors that are unique to high altitude. D) analyze the soils found in the vicinity of these trees, looking for unique chemicals that may support their growth. E) collect data on temperature, wind, and precipitation at several of these locations for a year.
Answer: C
38 38) How is habitat fragmentation related to biodiversity loss? A) Less carbon dioxide is absorbed by plants in fragmented habitats. B) In fragmented habitats, more soil erosion takes place. C) Populations of organisms in fragments are smaller and, thus, more susceptible to extinction. D) Animals are forced out of smaller habitat fragments. E) Fragments generate silt that negatively affects sensitive river and stream organisms.
Answer: C
38 In presenting data that result from an experiment, a group of students show that most of their measurements fall on a straight diagonal line on their graph. However, two of their data points are "outliers" and fall far to one side of the expected relationship. What should they do? A) Do not show these points but write a footnote that the graph represents the correct data. B) Average several trials and therefore rule out the improbable results. C) Show all results obtained and then try to explore the reason(s) for these outliers. D) Throw out this set of data and try again. E) Change the details of the experiment until they can obtain the expected results.
Answer: C
38 The accumulation of free oxygen in Earth's atmosphere began A) with the origin of life and respiratory metabolism. B) with the origin of photosynthetic bacteria that had photosystem I. C) with the origin of cyanobacteria that had both photosystem I and photosystem II. D) with the origin of chloroplasts in photosynthetic eukaryotic algae. E) with the origin of land plants.
Answer: C
38 What is the voltage across a membrane called? A) water potential B) chemical gradient C) membrane potential D) osmotic potential E) electrochemical gradient
Answer: C
39 Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? A) denaturization of the enzyme B) allosteric inhibition C) competitive inhibition D) saturation of the enzyme activity E) insufficient cofactors
Answer: C
39 Which of the following is the best description of a control for an experiment? A) The control group is kept in an unchanging environment. B) The control is left alone by the experimenters. C) The control group is matched with the experimental group except for the one experimental variable. D) The control group is exposed to only one variable rather than several. E) Only the experimental group is tested or measured.
Answer: C
4 4) Extinction is a natural phenomenon. It is estimated that 99% of all species that ever lived are now extinct. Why then do we say that we are now experiencing an extinction (loss of biodiversity) crisis? A) Humans are ethically responsible for protecting endangered species. B) Scientists have finally identified most of the species on Earth and are thus able to quantify the number of species becoming extinct. C) The current rate of extinction is high and human activities threaten biodiversity at all levels. D) Humans have greater medical needs than at any other time in history, and many potential medicinal compounds are being lost as plant species become extinct. E) Most biodiversity hot spots have been destroyed by recent ecological disasters.
Answer: C
4 Which of the following is characterized by a cell releasing a signal molecule into the environment, followed by a number of cells in the immediate vicinity responding? A) hormonal signaling B) autocrine signaling C) paracrine signaling D) endocrine signaling E) synaptic signaling
Answer: C
4 Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? A) animal B) plant C) archaea D) fungi E) protists
Answer: C
4 Which of the following types of molecules are the major structural components of the cell membrane? A) phospholipids and cellulose B) nucleic acids and proteins C) phospholipids and proteins D) proteins and cellulose E) glycoproteins and cholesterol
Answer: C
40 40) In which of the following situations would you expect to find the largest number of K-selected individuals? A) a recently abandoned agricultural field in Ohio B) the sand dune communities of south Lake Michigan C) the flora and fauna of a coral reef in the Caribbean D) South Florida after a hurricane E) a newly emergent volcanic island
Answer: C
40 40) Which of the following is consistent with forest fragmentation research? A) Productivity is the same in both fragmented forests and forest interiors. B) Edge communities consistently have low species diversity. C) Forest-interior species show declines in small patch communities. D) New-edge species that migrate in do not seem to compete with forest species and often increase biodiversity in fragmented forests. E) Species diversity is always lower in fragmented forests when compared to forest interiors in the same region.
Answer: C
59 card image A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in Figure 13.4. 59) A female with a paternal set of one orange and one long gene chromosome and a maternal set comprised of one blue and one short gene chromosome is expected to produce which of the following types of eggs after meiosis? A) All eggs will have maternal types of gene combinations. B) All eggs will have paternal types of gene combinations. C) Half the eggs will have maternal and half will have paternal combinations. D) Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations. E) Each egg has a three-fourths chance of having blue long, one-fourth blue short, three-fourths orange long, or one-fourth orange short combinations.
Answer: D
40 40) Which of the following statements best describes the effect of climate on biome distribution? A) Average annual temperature and precipitation are sufficient to predict which biome will be found in an area. B) Seasonal fluctuation of temperature is not a limiting factor in biome distribution if areas have the same annual temperature and precipitation means. C) Not only is the average climate important in determining biome distribution but so is the pattern of climatic variation. D) Temperate forests and grasslands are different biomes because they receive a different quality and quantity of sunlight, even though they have essentially the same annual temperature and precipitation. E) Correlation of climate with biome distribution is sufficient to determine the cause of biome patterns.
Answer: C
40 card image Which of the structures illustrated above is an impossible covalently bonded molecule? A) A B) B C) C D) D E) E
Answer: C
59 card image Which molecules shown above will form hydrogen bonds with water? A) Only D will form hydrogen bonds with water. B) All of these molecules will form hydrogen bonds with water. C) None of these molecules will form hydrogen bonds with water. D) All of these molecules except B will form hydrogen bonds with water. E) Only C, D, and E will form hydrogen bonds with water.
Answer: D
70 70) How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8(2n = 8)? A) 2 B) 4 C) 8 D) 16 E) 32
Answer: D
41 41) Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? A) Cancer cells are no longer density dependent. B) Cancer cells are no longer anchorage dependent. C) Chromosomally abnormal cells can still go through cell cycle checkpoints. D) Chromosomally abnormal cells still have normal metabolism. E) Transformation introduces new chromosomes into cells.
Answer: C
41 41) How are movement corridors potentially harmful to certain species? A) They increase inbreeding. B) They promote dispersion. C) They spread disease and parasites. D) They increase genetic diversity. E) They allow seasonal migration.
Answer: C
41 41) Which of the following best describes the consequences of white-band disease in Caribbean coral reefs? A) Staghorn coral has been decimated by the pathogen, and Elkhorn coral has taken its place. B) Key habitat for lobsters, snappers, and other reef fishes has improved. C) Algal species take the place of the dead coral, and the fish community is dominated by herbivores. D) Algal species take over and the overall reef diversity increases due to increases in primary productivity. E) Other coral species take the place of the affected Staghorn and Elkhorn species.
Answer: C
41 A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from A) a bacterium. B) an animal, but not a plant. C) nearly any eukaryotic organism. D) any multicellular organism, like a plant or an animal. E) any kind of organism.
Answer: C
41 How many electron pairs are shared between carbon atoms in a molecule that has the formula C₂H₄? A) 0 B) 1 C) 2 D) 3 E) 4
Answer: C
70 How many grams of acetic acid (C₂H₄O₂) would you use to make 10 L of a 0.1 M aqueous solution of acetic acid? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) A) 10 g B) 0.1 g C) 6.0 g D) 60 g E) 0.6 g
Answer: D
41 What are scaffolding proteins? A) ladderlike proteins that allow receptor-ligand complexes to climb through cells from one position to another B) microtubular protein arrays that allow lipid-soluble hormones to get from the cell membrane to the nuclear pores C) large molecules to which several relay proteins attach to facilitate cascade effects D) relay proteins that orient receptors and their ligands in appropriate directions to facilitate their complexing E) proteins that can reach into the nucleus of a cell to affect transcription
Answer: C
6 Knowing just the atomic mass of an element allows inferences about which of the following? A) the chemical properties of the element B) the number of protons in the element C) the number of neutrons in the element D) the number of protons plus neutrons in the element E) both the number of protons and the chemical properties of the element
Answer: D
42 42) Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? A) metastasis B) changes in the order of cell cycle stages C) lack of appropriate cell death D) inability to form spindles E) inability of chromosomes to meet at the metaphase plate
Answer: C
42 42) Biodiversity hot spots are not necessarily the best choice for nature preserves because A) hot spots are situated in remote areas not accessible to wildlife viewers. B) their ecological importance makes land purchase very expensive. C) a hot spot for one group of organisms may not be a hot spot for another group. D) hot spots are designated by abiotic factors present, not biotic factors. E) designated hot spots change on a daily basis.
Answer: C
42 42) In the evolution of whelk-eating behavior in crows, which of the following was optimized through natural selection? A) the average number of drops required to break the shell B) the average height a bird flew to drop a shell C) the average total energy used to break shells D) the average size of the shells dropped by the birds E) the average thickness of the shells dropped by the birds
Answer: C
42 In a high school laboratory, which of the following constitutes an experiment? I. learning to use a microscope by examining fixed specimens on slides II. being able to examine swimming protists under a microscope III. extracting pigments from plant leaves and separating the types of pigments for identification IV. preparing root tips for examination by staining them A) I only B) II only C) III only D) II and III only E) II, III, and IV
Answer: C
42 The movement of potassium into an animal cell requires A) low cellular concentrations of sodium. B) high cellular concentrations of potassium. C) an energy source such as ATP. D) a cotransport protein. E) a potassium channel protein.
Answer: C
42 The tertiary structure of a protein is the A) bonding together of several polypeptide chains by weak bonds. B) order in which amino acids are joined in a polypeptide chain. C) unique three-dimensional shape of the fully folded polypeptide. D) organization of a polypeptide chain into an α helix or β pleated sheet. E) overall protein structure resulting from the aggregation of two or more polypeptide subunits.
Answer: C
43 GTPase activity is involved in the regulation of signal transduction because it A) increases the available concentration of phosphate. B) decreases the amount of G protein in the membrane. C) hydrolyzes GTP binding to G protein. D) converts cGMP to GTP. E) phosphorylates protein kinases.
Answer: C
43 Which of the following best describes a model organism? A) It is often pictured in textbooks and easy for students to imagine. B) It lends itself to many studies that are useful to beginning students. C) It is well studied, easy to grow, and results are widely applicable. D) It is small, inexpensive to raise, and lives a long time. E) It has been chosen for study by the earliest biologists.
Answer: C
44 44) Why do neurons and some other specialized cells divide infrequently? A) They no longer have active nuclei. B) They no longer carry receptors for signal molecules. C) They have been shunted into G₀. D) They can no longer bind Cdk to cyclin. E) They show a drop in MPF concentration.
Answer: C
71 71) The principle of competitive exclusion states that A) two species cannot coexist in the same habitat. B) competition between two species always causes extinction or emigration of one species. C) competition in a population promotes survival of the best-adapted individuals. D) two species that have exactly the same niche cannot coexist in a community. E) two species will stop reproducing until one species leaves the habitat.
Answer: D
44 44) Why is territoriality an adaptive behavior for songbirds maintaining populations at or near their carrying capacity? A) Songbirds expend a tremendous amount of energy defending territories so that they spend less time feeding their young and fledgling mortality increases. B) Only the fittest males defend territories and they attract the fittest females so the best genes are conveyed to the next generation. C) Songbird males defend territories commensurate with the size from which they can derive adequate resources for themselves, their mate, and their chicks. D) Many individuals are killed in the agonistic behaviors that go along with territorial defense. E) Adult songbirds make improvements to the territories they inhabit so that they can produce successfully fledged chicks.
Answer: C
44 At which level of protein structure are interactions between the side chains (R groups) most important? A) primary B) secondary C) tertiary D) quaternary E) all of the above
Answer: C
44 How many oxygen molecules (O₂) are required each time a molecule of glucose (C₆H₁₂O₆) is completely oxidized to carbon dioxide and water via aerobic respiration,? A) 1 B) 3 C) 6 D) 12 E) 30
Answer: C
44 Which of the following would increase the electrochemical potential across a membrane? A) a chloride channel B) a sucrose-proton cotransporter C) a proton pump D) a potassium channel E) both a proton pump and a potassium channel
Answer: C
45 45) Which of the following best describes the frequency of crossing over in mammals? A) ~50 per chromosome pair B) ~2 per meiotic cell C) at least 1-2 per chromosome pair D) ~1 per pair of sister chromatids E) a very rare event among hundreds of cells
Answer: C
45 If a solution has a pH of 7, this means that A) there are no H⁺ ions in the water. B) this is a solution of pure water. C) the concentration of H⁺ ions in the water equals the concentration of OH⁻ ions in the water. D) this is a solution of pure water, and the concentration of H⁺ ions in the water is 10⁻⁷ M. E) this is a solution of pure water, and the concentration of H⁺ ions equals the concentration of OH⁻ ions in the water.
Answer: C
45 When you have a severe fever, what grave consequence may occur if the fever is not controlled? A) destruction of your enzymes' primary structure B) removal of amine groups from your proteins C) change in the tertiary structure of your enzymes D) removal of the amino acids in active sites of your enzymes E) binding of your enzymes to inappropriate substrates
Answer: C
46 46) A skeletal muscle deprived of adequate ATP supplies will A) immediately relax. B) release all actin-myosin bonds. C) enter a state where actin and myosin are unable to separate. D) fire many more action potentials than usual and enter a state of "rigor." E) sequester all free calcium ions into the sarcoplasmic reticulum.
Answer: C
46 46) In terms of community ecology, why are pathogens more virulent now than ever before? A) More new pathogens have recently evolved. B) Host organisms have become more susceptible because of weakened immune systems. C) Human activities are transporting pathogens globally at an unprecedented rate. D) Medicines for treating pathogenic disease are in short supply. E) Sequencing of genes in pathogenic organisms is particularly difficult.
Answer: C
46 46) When homologous chromosomes crossover, what occurs? A) Two chromatids get tangled, resulting in one re-sequencing its DNA. B) Two sister chromatids exchange identical pieces of DNA. C) Specific proteins break the two strands and re-join them with their homologs. D) Each of the four DNA strands of a tetrad is broken and the pieces are mixed. E) Maternal alleles are "corrected" to be like paternal alleles and vice versa.
Answer: C
46 If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result? A) neurodegeneration B) activation of a developmental pathway found in the worm but not in humans C) a form of cancer in which there is insufficient apoptosis D) webbing of fingers or toes E) excess skin exfoliation
Answer: C
47 47) What is the fitness benefit of polygamy in birds that rear precocious young? A) Females will copulate with many males to ensure that all of their eggs are fertilized. B) Females don't have to decide on one mate, and can copulate with as many males as she deems worthy to share her genes with in reproduction. C) Fit males don't have to help feed and rear young and can spend this time seeking and mating with many females. D) Females don't have to spend time rearing young and can mate and rear additional broods during a breeding season. E) Both males and females spend little time with courtship and brood-rearing, and don't tax their own physiology so they can breed again in subsequent breeding seasons.
Answer: C
48 48) Which of the following is most key to understanding the demographic transition in human population growth? A) education of global famine B) improved worldwide health care C) voluntary reduction of family size D) improved sanitary conditions in the world's hospitals E) reduction of casualties of war
Answer: C
48 48) Which of the life cycles is typical for plants and some algae? A) I only B) II only C) III only D) I and II E) I and III
Answer: C
48 Equal volumes (5 mL) of vinegar from a freshly opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? A) 100 mL of pure water B) 100 mL of freshly brewed coffee C) 100 mL of household cleanser containing 0.5 M ammonia D) 100 mL of freshly squeezed orange juice E) 100 mL of tomato juice
Answer: C
48 Which of the following statements describes enzyme cooperativity? A) A multienzyme complex contains all the enzymes of a metabolic pathway. B) A product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway. C) A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits. D) Several substrate molecules can be catalyzed by the same enzyme. E) A substrate binds to an active site and inhibits cooperation between enzymes in a pathway.
Answer: C
48 card image Which of the groups above is a carboxyl functional group? A) A B) B C) C D) D E) E
Answer: C
49 49) How does phosphorus normally enter ecosystems? A) cellular respiration B) photosynthesis C) rock weathering D) vulcanism E) atmospheric phosphorous gas
Answer: C
49 For their second experiment, the students want to know whether the Dinobryon have to live in colonies or can be free living. How might they proceed? A) Observe each day to see whether new organisms are ever reproduced as single cells. B) Observe whether only specialized cells are able to divide to produce new colonies. C) Divide a sample into single cells and measure the length of time they remain this way. D) Divide a sample into single cells and observe them. E) Divide a sample into single cells and see whether they come back together.
Answer: C
49 If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized by carbon dioxide and water, how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water? A) 0 B) 1 C) 12 D) 14 E) 15
Answer: C
49 Which of the following contain the 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules? A) both motile cilia and primary (nonmotile) cilia B) centrioles only C) both flagella and motile cilia D) both basal bodies and primary (nonmotile) cilia E) both centrioles and basal bodies
Answer: C
49 card image Which of the groups above is an acidic functional group that can dissociate and release H⁺ into a solution? A) A B) B C) C D) D E) E
Answer: C
5 5) Photosynthetic organisms are unique to most ecosystems because they A) synthesize organic compounds they obtain from decaying heterotrophs. B) synthesize inorganic compounds from organic compounds. C) use light energy to synthesize organic compounds. D) use chemical energy to synthesize organic compounds. E) convert light energy into matter.
Answer: C
5 In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function? A) formation of mating complexes B) secretion of apoptotic signals C) aggregation of bacteria that can cause cavities D) secretion of substances that inhibit foreign bacteria E) digestion of unwanted parasite populations
Answer: C
5 To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology? A) evolution B) emergent properties C) reductionism D) the cell theory E) feedback regulation
Answer: C
5 Which of the following people was the first to synthesize an organic compound, urea, from inorganic starting materials? A) Stanley Miller B) Jakob Berzelius C) Friedrich Wohler D) Hermann Kolbe E) August Kekulé
Answer: C
5 Why is each element unique and different from other elements in chemical properties? A) Each element has a unique atomic mass. B) Each element has a unique atomic weight. C) Each element has a unique number of protons in its nucleus. D) Each element has a unique number of neutrons in its nucleus. E) Each element has different radioactive properties.
Answer: C
50 50) Which statement is true with regard to human population growth? A) It is at a zero reproduction rate. B) Its rate of increase continues to grow at an exponential rate. C) Its rate of growth is slowing. D) Its rate of growth is increasing. E) There is no scientific prediction that can be made about human population growth.
Answer: C
50 Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to A) form cleavage furrows during cell division. B) migrate by amoeboid movement. C) separate chromosomes during cell division. D) extend pseudopods. E) maintain the shape of the nucleus.
Answer: C
50 Which of the following is an example of cooperativity? A) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway B) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway C) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three D) the effect of increasing temperature on the rate of an enzymatic reaction E) binding of an ATP molecule along with one of the substrate molecules in an active site
Answer: C
51 51) You have a series of cells, all of which were derived from tumors, and you first need to find out which ones are malignant. What could you do? A) See which ones are not overproliferating. B) Find out which ones have a higher rate of apoptosis. C) Karyotype samples to look for unusual size and number of chromosomes. D) Measure metastasis. E) Time their cell cycles.
Answer: C
51 In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve? A) It allows for an increased rate of glycolysis. B) It allows for an increased rate of the citric acid cycle. C) It increases the surface for oxidative phosphorylation. D) It increases the surface for substrate-level phosphorylation. E) It allows the liver cell to have fewer mitochondria.
Answer: C
51 The difference between pinocytosis and receptor-mediated endocytosis is that A) pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well. B) pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area. C) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. D) pinocytosis requires cellular energy, but receptor-mediated endocytosis does not. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.
Answer: C
51 The human population's life expectancy has increased significantly but seems to have an upper limit. Which of the following might be described as an ecological consequence of passing that upper limit by regulating cell death? A) an increase in the relative frequency of deaths from cancer B) an increased need for gerontologists and other professionals to care for the elderly C) an increase in the total population of humans on the planet D) a decrease in the ratio of younger to older members of the population E) a decrease in the birth rate
Answer: C
52 52) This causes extremely high levels of toxic chemicals in fish-eating birds. A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: C
52 Brown fat cells produce a protein called thermogenin in their mitochondrial inner membrane. Thermogenin is a channel for facilitated transport of protons across the membrane. What will occur in the brown fat cells when they produce thermogenin? A) ATP synthesis and heat generation will both increase. B) ATP synthesis will increase, and heat generation will decrease. C) ATP synthesis will decrease, and heat generation will increase. D) ATP synthesis and heat generation will both decrease. E) ATP synthesis and heat generation will stay the same.
Answer: C
52 In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? A) on the outside of vesicles B) on the inside surface of the cell membrane C) on the inside surface of the vesicle D) on the outer surface of the nucleus E) on the ER
Answer: C
52 card image The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all. 52) Which climograph shows the climate for location 3? A) B B) C C) D D) E E) F
Answer: C
53 An important group of peripheral membrane proteins are enzymes such as the phospholipases that cleave the head groups of phospholipids. What properties must these enzymes exhibit? A) resistance to degradation B) independence from cofactor interaction C) water solubility D) lipid solubility E) membrane-spanning domains
Answer: C
53 In a mitochondrion, if the matrix ATP concentration is high, and the intermembrane space proton concentration is too low to generate sufficient proton-motive force, then A) ATP synthase will increase the rate of ATP synthesis. B) ATP synthase will stop working. C) ATP synthase will hydrolyze ATP and pump protons into the intermembrane space. D) ATP synthase will hydrolyze ATP and pump protons into the matrix.
Answer: C
53 card image In the figure, the dots in the space between the two structures represent which of the following? A) receptor molecules B) signal transducers C) neurotransmitters D) hormones E) pheromones
Answer: C
54 54) Which of the following does not have a coefficient of relatedness of 0.5? A) a father to his daughter B) a mother to her son C) an uncle to his nephew D) a brother to his brother E) a sister to her brother
Answer: C
54 54) Why do logged tropical rain forest soils typically have nutrient-poor soils? A) Tropical bedrock contains little phosphorous. B) Logging results in soil temperatures that are lethal to nitrogen-fixing bacteria. C) Most of the nutrients in the ecosystem are removed in the harvested timber. D) The cation exchange capacity of the soil is reversed as a result of logging. E) Nutrients evaporate easily into the atmosphere in the post-logged forest.
Answer: C
54 In experimental tests of enzyme evolution, where a gene encoding an enzyme is subjected to multiple cycles of random mutagenesis and selection for altered substrate specificity, the resulting enzyme had multiple amino acid changes associated with altered substrate specificity. Where in the enzyme were these amino acid changes located? A) only in the active site B) only in the active site or near the active site C) in or near the active site and at surface sites away from the active site D) only at surface sites away from the active site E) only in the hydrophobic interior of the folded protein
Answer: C
54 card image How many grams would be equal to 1 mol of the compound shown in the figure above? (carbon = 12, oxygen = 16, hydrogen = 1) A) 29 B) 30 C) 60 D) 150 E) 342
Answer: C
54 card image Use the following diagram of a hypothetical food web to answer the following question. The arrows represent the transfer of food energy between the various trophic levels. Figure 54.3 54) Which letter represents an organism that could be a primary consumer? A) A B) B C) C D) D E) E
Answer: C
54 card image Which molecule shown above has a carbonyl functional group in the form of a ketone? A) A B) B C) C D) D E) E
Answer: C
55 55) Animals that help other animals of the same species A) have excess energy reserves. B) are bigger and stronger than the other animals. C) are usually related to the other animals. D) are always male. E) have defective genes controlling their behavior.
Answer: C
55 How might an amino acid change at a site distant from the active site of the enzyme alter the enzyme's substrate specificity? A) by changing the enzyme's stability B) by changing the enzyme's location in the cell C) by changing the shape of the protein D) by changing the enzyme's pH optimum E) an amino acid change away from the active site cannot alter the enzyme's substrate specificity
Answer: C
55 Which of the following statements about the cytoskeleton is true? A) The dynamic aspect of cytoskeletal function is made possible by the assembly and disassembly of a large variety of proteins into complex aggregates. B) Microfilaments are structurally rigid and resist compression, whereas microtubules resist tension (stretching). C) Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other. D) Chemicals that block the assembly of the cytoskeleton would cause little effect on the cell's response to external signals and stimuli. E) Transport vesicles among the membranes of the endomembrane system produce the cytoskeleton.
Answer: C
55 card image The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all. 55) Which of the following best substantiates why location 3 is an equatorial (tropical) climate? A) It has a monsoon season during the winter months. B) It has consistent monthly averages for rainfall. C) The temperature is high for each monthly average. D) The temperatures reach 100°F during some months. E) The temperatures are lower in June, July, and August.
Answer: C
55 card image Which drawing in the figure above depicts the electron configuration of an atom that can form covalent bonds with two hydrogen atoms? A) A B) B C) C D) D E) E
Answer: C
56 The alternative pathways of photosynthesis using the C₄ or CAM systems are said to be compromises. Why? A) Each one minimizes both water loss and rate of photosynthesis. B) C₄ compromises on water loss and CAM compromises on photorespiration. C) Both minimize photorespiration but expend more ATP during carbon fixation. D) CAM plants allow more water loss, while C₄ plants allow less CO₂ into the plant. E) C₄ plants allow less water loss but CAM plants allow more water loss.
Answer: C
56 card image 56) Study the information above about quail habitats. Which of these represents the best quail habitat in terms of fragmentation and edge? A) A B) B C) C D) D E) E
Answer: C
56 card image 56) Which of the following graphs illustrates the population growth curve of single bacterium growing in a flask of ideal medium at optimum temperature over a 24-hour period? A. SEE IMAGE B. SEE IMAGE C. SEE IMAGE D. SEE IMAGE E. SEE IMAGE
Answer: C
56 card image The diagram shows a generalized cross section of the marine environment with various zones labeled with letters. Choose the letter that best answers the question. Letters may be used once, more than once, or not at all 56) Which zone has a condition of constant temperature? A) A B) B C) C D) D E) E
Answer: C
56 card image Use the following diagram of five islands formed at around the same time near a particular mainland, as well as MacArthur and Wilson's island biogeography principles, to answer the following question. Figure 54.4 56) Which island would likely exhibit the most impoverished species diversity? A) A B) B C) C D) D E) E
Answer: C
57 57) Which of the following statements is true? A) An ecosystem's trophic structure determines the rate at which energy cycles within the system. B) At any point in time, it is impossible for consumers to outnumber producers in an ecosystem. C) Chemoautotrophic prokaryotes near deep-sea vents are primary producers. D) There has been a well-documented increase in atmospheric nitrogen over the past several decades. E) The reservoir of ecosystem phosphorous is the atmosphere.
Answer: C
57 All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distinct from the others in their composition? A) microtubules B) microfilaments C) plant cell walls D) intermediate filaments E) nuclear lamina
Answer: C
57 card image Which component is a microfilament of the cytoskeleton? A) A B) B C) C D) D E) E
Answer: C
58 Systems biology is mainly an attempt to A) analyze genomes from different species. B) simplify complex problems by reducing the system into smaller, less complex units. C) understand the behavior of entire biological systems. D) build high-throughput machines for the rapid acquisition of biological data. E) speed up the technological application of scientific knowledge.
Answer: C
58 The next question presumes that you have at least once visited and have some knowledge of the fast-food restaurant McDonald's. Use your knowledge of McDonald's and your understanding of community ecology to answer the following questions about an ecological community, McDonaldland. 58) In McDonaldland, which of the following would be an example of an introduced species? A) Big Mac B) Quarter Pounder C) BK Whopper D) Filet-O-Fish E) Double Cheeseburger
Answer: C
58 Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base and a phosphate group B) a nitrogenous base and a pentose sugar C) a nitrogenous base, a phosphate group, and a pentose sugar D) a phosphate group and an adenine or uracil E) a pentose sugar and a purine or pyrimidine
Answer: C
58 card image A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in Figure 13.4. 58) If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, she will produce which of the following egg types? A) only blue short gene eggs B) only orange short gene eggs C) one-half blue short and one-half orange short gene eggs D) three-fourths blue long and one-fourth orange short gene eggs E) three-fourths blue short and one-fourth orange short gene eggs
Answer: C
58 card image The diagram shows a generalized cross section of the marine environment with various zones labeled with letters. Choose the letter that best answers the question. Letters may be used once, more than once, or not at all 58) Which zone is comprised largely of detritus-feeding organisms? A) A B) B C) C D) D E) E
Answer: C
59 Protists and bacteria are grouped into different domains because A) protists eat bacteria. B) bacteria are not made of cells. C) protists have a membrane-bounded nucleus, which bacterial cells lack. D) bacteria decompose protists. E) protists are photosynthetic.
Answer: C
59 card image 59) At which of the numbered regions would you expect to find cells at metaphase? A) I and IV B) II only C) III only D) IV only E) V only
Answer: C
60 60) When levels of CO₂ are experimentally increased in a typical grassland community, C₃ plants generally respond with a greater increase in productivity than C₄ plants. This is because A) C₃ plants are more efficient in their use of CO₂. B) C₃ plants are able to obtain the same amount of CO₂ by keeping their stomata open for shorter periods of time. C) C₄ plants don't use CO₂ as their source of carbon. D) C₃ plants are more limited by CO₂ availability because they lack mechanisms to prevent transpirational water loss. E) C₃ plants have special adaptations for CO₂ uptake, such as larger stomata.
Answer: D
61 Humans have receptors for two kinds of beta adrenergic compounds such as catecholamines to control cardiac muscle contractions. Some are beta 1 receptors that promote increased heart rate. Other drugs, called beta blockers, slow heart rate. Smooth muscle cells, however, have beta 2 receptors, which mediate muscle relaxation. Blockers of these effects are sometimes used to treat asthma. Beta 2 antagonist drugs might also be used most effectively for which of the following? A) cardiac arrhythmias B) increased gastric acid production C) neuropathy of the extremities D) increasing low blood pressure E) decreasing peristalsis
Answer: D
61 card image Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different? A) Green and yellow wavelengths inhibit the absorption of red and blue wavelengths. B) Bright sunlight destroys photosynthetic pigments. C) Oxygen given off during photosynthesis interferes with the absorption of light. D) Other pigments absorb light in addition to chlorophyll a. E) Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis.
Answer: D
71 Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. An outcome of this experiment was to help determine A) the relationship between heterotrophic and autotrophic organisms. B) the relationship between wavelengths of light and the rate of aerobic respiration. C) the relationship between wavelengths of light and the amount of heat released. D) the relationship between wavelengths of light and the rate of photosynthesis. E) the relationship between the concentration of carbon dioxide and the rate of photosynthesis.
Answer: D
73 73) Based on current growth rates, Earth's human population in 2012 will be closest to A) 2 million. B) 3 billion. C) 4 billion. D) 7 billion. E) 10 billion.
Answer: D
73 A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, A) mitochondria and chloroplasts. B) chloroplasts and peroxisomes. C) peroxisomes and chloroplasts. D) chloroplasts and mitochondria. E) mitochondria and peroxisomes.
Answer: D
73 Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur? A) in photosynthetic cells in the light, while photosynthesis occurs concurrently B) in nonphotosynthesizing cells only C) in cells that are storing glucose only D) in all cells all the time E) in photosynthesizing cells in the light and in other tissues in the dark
Answer: D
59 card image Flycatcher birds that migrate from Africa to Europe feed their nestlings a diet that is almost exclusively moth caterpillars. The graph below shows the mean dates of arrival, bird hatching, and peak caterpillar season for the years 1980 and 2000. 59) Why were ecologists concerned about the shift in the peak caterpillar season from June 3, 1980, to May 15, 2000? A) The caterpillars would have eaten much of the foliage of the trees where flycatchers would have nested, rendering their nests more open to predation. B) The earlier hatching of caterpillars would compete with other insect larval forms which the flycatchers would also use to feed their young. C) The 2000 flycatcher nestlings would miss the peak caterpillar season and might not be as well fed. D) The flycatchers would have to migrate sooner to match their brood-rearing to the time of peak caterpillar season. E) Pesticides, which have a negative effect on the ecosystem, would have to be used to control the earlier outbreak of caterpillar hatching.
Answer: C
74 card image 74) Myosin filaments without actin overlap are in which section of the figure? A) A B) B C) C D) D E) E
Answer: D
75 The light reactions of photosynthesis supply the Calvin cycle with A) light energy. B) CO₂ and ATP. C) H₂O and NADPH. D) ATP and NADPH. E) sugar and O₂.
Answer: D
59 card image The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. Initially, in terms of tonicity, the solution in side A with respect to that in side B is A) hypotonic. B) plasmolyzed. C) isotonic. D) saturated. E) hypertonic.
Answer: C
75 Which structure is common to plant and animal cells? A) chloroplast B) wall made of cellulose C) central vacuole D) mitochondrion E) centriole
Answer: D
6 6) Although extinction is a natural process, current extinctions are of concern to environmentalists because A) more animals than ever before are going extinct. B) most current extinctions are caused by introduced species. C) the rate of extinction is unusually high. D) current extinction is primarily affecting plant diversity. E) None of the options are correct.
Answer: C
75 You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells? A) blood or tissue type of the patient B) hydrophobicity of the drug molecule C) lack of charge on the drug molecule D) similarity of the drug molecule to other molecules transported by the target cells E) lipid composition of the target cells' plasma membrane
Answer: D
75 card image Which of the following statements is true regarding the molecule illustrated in Figure 5.2? A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis. C) Molecules of this type are usually liquid at room temperature. D) It is a saturated fatty acid and a diet rich in this molecule may contribute to atherosclerosis. E) It is a saturated fatty acid, a diet rich in this molecule may contribute to atherosclerosis, and molecules of this type are usually liquid at room temperature.
Answer: D
6 6) Why is the climate drier on the leeward side of mountain ranges that are subjected to prevailing winds? A) Deserts usually are found on the leeward side of mountain ranges. B) The sun illuminates the leeward side of mountain ranges at a more direct angle, converting to heat energy, which evaporates most of the water present. C) Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving only dry air to descend the leeward side. D) Air masses pushed by the prevailing winds are stopped by mountain ranges and the moisture is used up in the stagnant air masses on the leeward side. E) More organisms live on the sheltered, leeward side of mountain ranges where their utilization of water lowers the amount available when compared to the windward side.
Answer: C
6 In autotrophic bacteria, where are the enzymes located that can carry on carbon fixation (reduction of carbon dioxide to carbohydrate)? A) in chloroplast membranes B) in chloroplast stroma C) in the cytosol D) in the nucleoid E) in the infolded plasma membrane
Answer: C
60 Humans have receptors for two kinds of beta adrenergic compounds such as catecholamines to control cardiac muscle contractions. Some are beta 1 receptors that promote increased heart rate. Other drugs, called beta blockers, slow heart rate. Smooth muscle cells, however, have beta 2 receptors, which mediate muscle relaxation. Blockers of these effects are sometimes used to treat asthma. The use of beta 2 antagonist drugs may be useful in asthma because they may A) increase constriction of the skeletal muscle of the chest wall. B) increase heart rate and therefore allow the patient to get more oxygen circulated. C) dilate the bronchioles by relaxing their smooth muscle. D) override the beta blockers that the patient is already taking. E) obstruct all G protein-mediated receptors.
Answer: C
60 Plants photosynthesize only in the light. Plants respire A) in the dark only. B) in the light only. C) both in light and dark. D) never-they get their ATP from photophosphorylation. E) only when excessive light energy induces photorespiration.
Answer: C
76 76) The discipline that applies ecological principles to returning degraded ecosystems to a more natural state is known as A) population viability analysis. B) landscape ecology. C) conservation ecology. D) restoration ecology. E) resource conservation.
Answer: D
60 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? A) plasma membrane → primary cell wall → cytoplasm → vacuole B) secondary cell wall → plasma membrane → primary cell wall → cytoplasm → vacuole C) primary cell wall → plasma membrane → cytoplasm → vacuole D) primary cell wall → plasma membrane → lysosome → cytoplasm → vacuole E) primary cell wall → plasma membrane → cytoplasm → secondary cell wall → vacuole
Answer: C
60 card image 60) MPF reaches its threshold concentration at the end of this stage. A) I B) II C) III D) IV E) V
Answer: C
60 card image After the system reaches equilibrium, what changes are observed? A) The molarity of sucrose and glucose are equal on both sides. B) The molarity of glucose is higher in side A than in side B. C) The water level is higher in side A than in side B. D) The water level is unchanged. E) The water level is higher in side B than in side A.
Answer: C
60 card image Which drawing in the figure above depicts an atom with a valence of 2? A) A B) B C) C D) D E) E
Answer: C
61 If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? A) 10 B) 20 C) 40 D) 80 E) impossible to tell from the information given
Answer: C
76 76) Which of the following could qualify as a top-down control on a grassland community? A) limitation of plant biomass by rainfall amount B) influence of temperature on competition among plants C) influence of soil nutrients on the abundance of grasses versus wildflowers D) effect of grazing intensity by bison on plant species diversity E) effect of humidity on plant growth rates
Answer: D
78 Which of the following statements is a correct distinction between autotrophs and heterotrophs? A) Only heterotrophs require chemical compounds from the environment. B) Cellular respiration is unique to heterotrophs. C) Only heterotrophs have mitochondria. D) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO₂ and other nutrients that are inorganic. E) Only heterotrophs require oxygen.
Answer: D
62 Experts in white-tailed deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in "yarding" areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation. 62) This observation best illustrates which of the following principles about factors that limit distribution of organisms? A) Abiotic factors, such as weather extremes, ultimately limit distribution. B) Organisms will face extinction unless they adapt to conditions or evolve new mechanisms for survival. C) Environmental factors are limiting not only in amount but also in longevity. D) Daily accumulations in snow depth gradually add up to cause increased deer mortality. E) Temporary extremes in weather conditions usually result in high mortality in the deer population.
Answer: C
62 One function of both alcohol fermentation and lactic acid fermentation is to A) reduce NAD⁺ to NADH. B) reduce FAD⁺ to FADH₂. C) oxidize NADH to NAD⁺. D) reduce FADH₂ to FAD⁺. E) do none of the above.
Answer: C
62 Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because A) they are species specific. B) they always lead to the same cellular response. C) they amplify the original signal manyfold. D) they counter the harmful effects of phosphatases. E) the number of molecules used is small and fixed.
Answer: C
62 There is a group of invertebrate animals called rotifers, among which a particular group of species reproduces, as far as is known, only asexually. These rotifers, however, have survived a long evolutionary history without evidence of having been overcome by excessive mutations. 62) In these asexual rotifers, how does variation occur without meiosis and fertilization? A) The rotifers have evolved a different mechanism to exchange DNA. B) Rotifers must produce haploid spores. C) Variation is caused by mutation and maintained by selection. D) Some rotifers must selectively lose chromosomes. E) Rotifers must live only in specialized environments.
Answer: C
62 You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCl and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be A) 2.0. B) 12.0. C) 7.0. D) 5.0. E) 9.0.
Answer: C
62 card image In the figure above, how many unpaired electrons does phosphorus have in its valence shell? A) 15 B) 2 C) 3 D) 7 E) 5
Answer: C
62 card image The following questions refer to Figure 53.3, which depicts the age structure of three populations. 62) Which population(s) appear(s) to be stable? A) I B) II C) III D) I and II E) II and III
Answer: C
79 What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell? A) ER → Golgi → nucleus B) Golgi →ER →lysosome C) nucleus →ER →Golgi D) ER →Golgi →vesicles that fuse with plasma membrane E) ER →lysosomes →vesicles that fuse with plasma membrane
Answer: D
79 Which of the following processes includes all others? A) osmosis B) diffusion of a solute across a membrane C) facilitated diffusion D) passive transport E) transport of an ion down its electrochemical gradient
Answer: D
63 In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce are displaced from their normal vertical alignment. 63) What might be the adaptive significance of these unusual forests growing the way they do in this marginal habitat? A) Needles are adapted to withstand cold arctic temperatures. B) Branches are adapted to absorb more CO₂ with this displaced alignment. C) Taproot formation is impossible, so trees developed shallow root beds. D) Trees are tilted so snow prevents them from breaking or tipping over. E) Trees tip so that they do not compete with each other for sunlight.
Answer: C
63 Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? A) peroxisomes B) desmosomes C) gap junctions D) extracellular matrix E) tight junctions
Answer: C
63 Which of the following is an example of qualitative data? A) The temperature decreased from 20°C to 15°C. B) The plant's height is 25 centimeters (cm). C) The fish swam in a zigzag motion. D) The six pairs of robins hatched an average of three chicks. E) The contents of the stomach are mixed every 20 seconds.
Answer: C
63 card image Five dialysis bags, constructed from a semipermeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed. Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment? A) A B) B C) C D) D E) E
Answer: C
64 64) An endoskeleton is the primary body support for the A) annelids, including earthworms. B) insects, including beetles. C) cartilaginous fishes, including sharks. D) bivalves, including clams. E) crustaceans, including lobsters.
Answer: C
64 64) Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems? A) population ecology B) organismal ecology C) landscape ecology D) ecosystem ecology E) community ecology
Answer: C
64 card image The following questions refer to Figure 53.3, which depicts the age structure of three populations. 64) Assuming these age-structure diagrams describe human populations, which population(s) is (are) likely to experience zero population growth (ZPG)? A) I B) II C) III D) I and II E) II and III
Answer: C
65 Which of the following is a hydrophobic material? A) paper B) table salt C) wax D) sugar E) pasta
Answer: C
8 A dietary Calorie equals 1 kilocalorie. Which of the following statements correctly defines 1 kilocalorie? A) 1,000 calories, or the amount of heat required to raise the temperature of 1 g of water by 1,000°C B) 100 calories, or the amount of heat required to raise the temperature of 100 g of water by 1°C C) 10,000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°F D) 1,000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°C E) 1,000 calories, or the amount of heat required to raise the temperature of 100 g of water by 100°C
Answer: D
8 Oxygen has an atomic number of 8 and a mass number of 16. Thus, what is the atomic mass of an oxygen atom? A) exactly 8 grams B) exactly 8 daltons C) approximately 16 grams D) approximately 16 daltons E) 24 amu (atomic mass units)
Answer: D
65 card image Refer to Figure 53.4 and then answer the following questions. Figure 53.4: Infant mortality and life expectancy at birth in developed and developing countries (data as of 2005). 65) What is a logical conclusion that can be drawn from the graphs above? A) Developed countries have lower infant mortality rates and lower life expectancy than developing countries. B) Developed countries have higher infant mortality rates and lower life expectancy than developing countries. C) Developed countries have lower infant mortality rates and higher life expectancy than developing countries. D) Developed countries have higher infant mortality rates and higher life expectancy than developing countries. E) Developed countries have a life expectancy that is about 42 years more than life expectancy in developing countries.
Answer: C
66 66) Female spotted sandpipers aggressively court males and, after mating, leave the clutch of young for the male to incubate. This sequence may be repeated several times with different males until no available males remain, forcing the female to incubate her last clutch. Which of the following terms best describes this behavior? A) monogamy B) polygyny C) polyandry D) promiscuity E) certainty of paternity
Answer: C
66 66) Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex? A) Capture all remaining individuals in the population for captive breeding followed by reintroduction to the wild. B) Establish a reserve that protects the population's habitat. C) Introduce new individuals transported from other populations of the same species. D) Sterilize the least fit individuals in the population. E) Control populations of the endangered population's predators and competitors.
Answer: C
8 Which of the following statements is representative of the second law of thermodynamics? A) Conversion of energy from one form to another is always accompanied by some gain of free energy. B) Heat represents a form of energy that can be used by most organisms to do work. C) Without an input of energy, organisms would tend toward decreasing entropy. D) Cells require a constant input of energy to maintain their high level of organization. E) Every energy transformation by a cell decreases the entropy of the universe.
Answer: D
61 card image Use the following diagram from the text showing the spread of the cattle egret, Bubulcus ibis, since its arrival in the New World, to answer the following question. 61) How would an ecologist likely explain the expansion of the cattle egret? A) The areas to which the cattle egret has expanded have no cattle egret parasites. B) Climatic factors, such as temperature and precipitation, provide a suitable habitat for cattle egrets. C) There are no predators for cattle egrets in the New World, so they continue to expand their range. D) A habitat left unoccupied by native herons and egrets met the biotic and abiotic requirements of the cattle egret transplants and their descendants. E) The first egrets to colonize South America evolved into a new species capable of competing with the native species of herons and egrets.
Answer: D
62 62) One characteristic that distinguishes a population in an extinction vortex from most other populations is that A) its habitat is fragmented. B) it is a rare, top-level predator. C) its effective population size is much lower than its total population size. D) its genetic diversity is very low. E) it is not well adapted to edge conditions.
Answer: D
66 Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student—faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 66) The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that A) the presence of the pathogen made the experiment too contaminated to trust the results. B) their tissue culture methods needed to be relearned. C) infection causes lymphocytes to divide more rapidly. D) infection causes cell cultures in general to reproduce more rapidly. E) infection causes lymphocyte cultures to skip some parts of the cell cycle.
Answer: C
62 The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via which of the following? A) gap junctions B) the nucleus C) DNA and RNA D) integrins E) plasmodesmata
Answer: D
62 card image If you examine side A after three days, you should find A) a decrease in the concentration of NaCl and glucose and an increase in the water level. B) a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose. C) no net change in the system. D) a decrease in the concentration of NaCl and a decrease in the water level. E) no change in the concentration of NaCl and glucose and an increase in the water level.
Answer: D
62 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following in Figure 8.1 would be the same in either an enzyme-catalyzed or a noncatalyzed reaction? A) a B) b C) c D) d E) e
Answer: D
62 card image Use the data in Table 12.1 to answer the following question. (SEE IMAGE) The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma 62) The best conclusion concerning delta is that the cells A) contain no DNA. B) contain no RNA. C) contain only one chromosome that is very short. D) are actually in the G₀ phase. E) divide in the G₁ phase.
Answer: D
62 card image Which molecule shown above contains a functional group that cells use to transfer energy between organic molecules? A) A B) B C) C D) D E) E
Answer: D
63 Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane? A) receptor tyrosine kinase B) G protein-coupled receptor C) phosphorylated receptor tyrosine kinase dimer D) ligand-gated ion channel E) intracellular receptor
Answer: D
66 card image To identify the molecule that accepts CO₂, Calvin and Benson manipulated the carbon-fixation cycle by either cutting off CO₂ or cutting off light from cultures of photosynthetic algae. They then measured the concentrations of various metabolites immediately following the manipulation. How would these experiments help identify the CO₂ acceptor? Study Figure 10.2 to help you in determining the correct answer. A) The CO₂ acceptor concentration would decrease when either the CO₂ or light are cut off. B) The CO₂ acceptor concentration would increase when either the CO₂ or light are cut off. C) The CO₂ acceptor concentration would increase when the CO₂ is cut off, but decrease when the light is cut off. D) The CO₂ acceptor concentration would decrease when the CO₂ is cut off, but increase when the light is cut off. E) The CO₂ acceptor concentration would stay the same regardless of the CO₂ or light.
Answer: C
67 Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake? A) 4.0 M B) 10⁻¹⁰ M C) 10⁻⁴ M D) 10⁴ M E) 4%
Answer: C
67 Signals between the ECM and the cytoskeleton may be transmitted by A) fibronectin. B) proteoglycans. C) integrins. D) collagen. E) middle lamella.
Answer: C
67 card image 67) On the diagram of the nitrogen cycle, which number represents nitrite (NO₂)? A) 1 B) 2 C) 3 D) 4
Answer: C
67 card image What would be observed by live-cell fluorescence microscopy if HIV is endocytosed first, and then fuses with the endocytotic vesicle membrane? A) A spot of red fluorescence will remain on the infected cell's plasma membrane, marking the site of membrane fusion and HIV entry. B) The red fluorescent dye-labeled lipids will diffuse in the endocytotic vesicle membrane and become difficult to detect. C) A spot of red fluorescence will move into the infected cell's interior. D) A spot of red fluorescence will remain outside the cell after delivering the viral capsid. E) Fluorescence microscopy does not have enough resolution to visualize fluorescently labeled HIV virus particles.
Answer: C
63 Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? A) water's change in density when it condenses B) water's ability to dissolve molecules in the air C) the release of heat by the formation of hydrogen bonds D) the absorption of heat by the breaking of hydrogen bonds E) water's high surface tension
Answer: D
68 68) Although many chimpanzees live in environments containing oil palm nuts, members of only a few populations use stones to crack open the nuts. The likely explanation is that A) the behavioral difference is caused by genetic differences between populations. B) members of different populations have different nutritional requirements. C) the cultural tradition of using stones to crack nuts has arisen in only some populations. D) members of different populations differ in learning ability. E) members of different populations differ in manual dexterity.
Answer: C
63 Several organisms, primarily protists, have what are called intermediate mitotic organization. 63) These protists are intermediate in what sense? A) They reproduce by binary fission in their early stages of development and by mitosis when they are mature. B) They never coil up their chromosomes when they are dividing. C) They use mitotic division but only have circular chromosomes. D) They maintain a nuclear envelope during division. E) None of them form spindles.
Answer: D
68 Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells? A) Enzymatic activity was proportional to the amount of calcium added to a cell-free extract. B) Receptor studies indicated that epinephrine was a ligand. C) Glycogen breakdown was observed only when epinephrine was administered to intact cells. D) Glycogen breakdown was observed when epinephrine and glycogen phosphorylase were combined. E) Epinephrine was known to have different effects on different types of cells.
Answer: C
68 card image 68) The structure involved in equalizing the pressure between the ear and the atmosphere is represented by number A) 7. B) 1. C) 8. D) 9. E) 10.
Answer: C
69 69) If the DNA content of a diploid cell in the G₁ phase of the cell cycle is x, then the DNA content of a single cell at metaphase of meiosis II would be A) 0.25x. B) 0.5x. C) x. D) 2x. E) 4x.
Answer: C
69 Protein phosphorylation is commonly involved with all of the following except A) regulation of transcription by extracellular signaling molecules. B) enzyme activation. C) activation of G protein-coupled receptors. D) activation of receptor tyrosine kinases. E) activation of protein kinase molecules.
Answer: C
63 card image How many neutrons are present in the nucleus of a phosphorus-32 (³²P) atom (see the figure above)? A) 5 B) 15 C) 16 D) 17 E) 32
Answer: D
63 card image If ATP used by this plant is labeled with radioactive phosphorus, which molecule or molecules of the Calvin cycle will be radioactively labeled first? A) B only B) B and C only C) B, C, and D only D) B and E only E) B, C, D, and E
Answer: D
64 64) Which of the following is true of innate behaviors? A) Their expression is only weakly influenced by genes. B) They occur with or without environmental stimuli. C) They are limited to invertebrate animals. D) They are expressed in most individuals in a population. E) They occur in invertebrates and some vertebrates but not mammals.
Answer: D
64 A chemist wishes to make an organic molecule less acidic. Which of the following functional groups should be added to the molecule in order to do so? A) carboxyl B) sulfhydryl C) hydroxyl D) amino E) phosphate
Answer: D
64 Which of the following best describes the logic of scientific inquiry? A) If I generate a testable hypothesis, tests and observations will support it. B) If my prediction is correct, it will lead to a testable hypothesis. C) If my observations are accurate, they will support my hypothesis. D) If my hypothesis is correct, I can expect certain test results. E) If my experiments are set up right, they will lead to a testable hypothesis.
Answer: D
64 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the difference between the free-energy content of the reaction and the free-energy content of the products in Figure 8.1? A) a B) b C) c D) d E) e
Answer: D
65 65) A ball-and-socket joint connects A) the radius to the ulna. B) the radius to the humerus. C) the ulna to the humerus. D) the humerus to the scapula. E) the radius to the scapula.
Answer: D
65 card image Based on electron configuration, which of these elements in the figure above would exhibit a chemical behavior most like that of oxygen? A) carbon B) hydrogen C) nitrogen D) sulfur E) phosphorus
Answer: D
65 card image Diagram of a food web (arrows represent energy flow and letters represent species) 65) If the figure above represents a terrestrial food web, the combined biomass of C + D would probably be A) greater than the biomass of A. B) less than the biomass of H. C) greater than the biomass of B. D) less than the biomass of A + B. E) less than the biomass of E.
Answer: D
65 card image Which molecule(s) of the Calvin cycle is (are) also found in glycolysis? A) B, C, E, and 3-phosphoglycerate B) B, C, and E only C) 3-phosphoglycerate only D) B, C, D, and 3-phosphoglycerate only E) E only
Answer: D
66 66) Which of the following is true with respect to oligotrophic lakes and eutrophic lakes? A) Oligotrophic lakes are more subject to oxygen depletion. B) Rates of photosynthesis are lower in eutrophic lakes. C) Eutrophic lake water contains lower concentrations of nutrients. D) Eutrophic lakes are richer in nutrients. E) Sediments in oligotrophic lakes contain larger amounts of decomposable organic matter.
Answer: D
67 67) To measure the population of lake trout in a 250-hectare lake, 400 individual trout were netted and marked with a fin clip, then returned to the lake. The next week, the lake was netted again, and out of the 200 lake trout that were caught, 50 had fin clips. Using the capture-recapture estimate, the lake trout population size could be closest to which of the following? A) 160 B) 200 C) 400 D) 1,600 E) 80,000
Answer: D
67 Apoptosis involves all but which of the following? A) fragmentation of the DNA B) cell-signaling pathways C) activation of cellular enzymes D) lysis of the cell E) digestion of cellular contents by scavenger cells
Answer: D
69 The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the female teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. 69) Which of the following investigations might be most productive to show what the data on the teenagers might indicate? A) test male teenagers B) test teenagers who say they are not sexually active C) test female teens at different times in their menstrual cycles D) test relatives of the teens previously tested E) test teenagers from different school systems
Answer: C
69 card image What causes the shape of the molecule shown above? A) the configuration of the 2 p orbitals in the carbon atom B) the configuration of the 1 s orbital in the carbon atom C) the configuration of the sp hybrid orbitals of the electrons shared between the carbon and hydrogen atoms D) the packing of the carbon and hydrogen atoms in a crystal lattice E) hydrogen bonding configurations between the carbon and hydrogen atoms
Answer: C
7 7) Stimuli alter the activity of excitable sensory cells via A) integration. B) transmission. C) transduction. D) transcription. E) amplification.
Answer: C
7 7) To construct a reproductive table for a sexual species, one needs to A) assess sperm viability for the males in the population. B) keep track of all of the offspring of a cohort. C) keep track of the females in a cohort. D) keep track of all of the offspring of the females in a cohort. E) analyze the ratio of deaths to births in a cohort.
Answer: C
7 7) What type of signal is brief and can work among obstructions at night? A) olfactory B) visual C) auditory D) tactile E) magnetic
Answer: C
7 What is the reason that a modern electron microscope (TEM) can resolve biological images to the subnanometer level, as opposed to tens of nanometers achievable for the best super-resolution light microscope? A) The focal length of the electron microscope is significantly longer. B) Contrast is enhanced by staining with atoms of heavy metal. C) Electron beams have much shorter wavelengths than visible light. D) The electron microscope has a much greater ratio of image size to real size. E) The electron microscope cannot image whole cells at one time.
Answer: C
7 When a molecule of NAD⁺ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes A) dehydrogenated. B) oxidized. C) reduced. D) redoxed. E) hydrolyzed.
Answer: C
7 When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the blood glucose level is low, the pancreas secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the blood glucose level is the result of A) catalytic feedback B) positive feedback C) negative feedback D) bioinformatic regulation E) protein-protein interactions
Answer: C
70 70) Which statement about dispersal is false? A) Dispersal is a common component of the life cycles of plants and animals. B) Colonization of devastated areas after floods or volcanic eruptions depends on dispersal. C) Dispersal occurs only on an evolutionary time scale. D) Seeds are important dispersal stages in the life cycles of most flowering plants. E) The ability to disperse can expand the geographic distribution of a species.
Answer: C
70 Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. What did Engelmann conclude about the congregation of bacteria in the red and blue areas? A) Bacteria released excess carbon dioxide in these areas. B) Bacteria congregated in these areas due to an increase in the temperature of the red and blue light. C) Bacteria congregated in these areas because these areas had the most oxygen being released. D) Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths. E) Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.
Answer: C
70 card image 70) Vibrations of the tympanic membrane to the oval window are transmitted by the structures at which numbers? A) 1, 2, 3, and 4. B) 2, 3, and 4. C) 3 and 4. D) 4. E) 5.
Answer: C
71 Cystic fibrosis is a genetic disease in humans in which the CFTR protein, which functions as a chloride ion channel, is missing or nonfunctional in cell membranes. 71) The CFTR protein belongs to what category of membrane proteins? A) gap junctions B) aquaporins C) electrogenic ion pumps D) cotransporters E) hydrophilic channels
Answer: C
71 Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. Based on this information, which of the following is correct? A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate. B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate. C) Succinate is the substrate, and fumarate is the product. D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor. E) Malonic acid is the product, and fumarate is a competitive inhibitor.
Answer: C
72 72) As big as it is, the ocean is nutrient-limited. If you wanted to investigate this, one reasonable approach would be to A) follow whale migrations in order to determine where most nutrients are located. B) observe Antarctic Ocean productivity from year to year to see if it changes. C) experimentally enrich some areas of the ocean and compare their productivity to that of untreated areas. D) compare nutrient concentrations between the photic zone and the benthic zone in various marine locations. E) contrast nutrient uptake by autotrophs in marine locations that are different temperatures.
Answer: C
72 72) Based on the intermediate disturbance hypothesis, a community's species diversity is increased by A) frequent massive disturbance. B) stable conditions with no disturbance. C) moderate levels of disturbance. D) human intervention to eliminate disturbance. E) intensive disturbance by humans.
Answer: C
72 72) Scientific study of the population cycles of the snowshoe hare and its predator, the lynx, has revealed that A) the prey population is controlled by predators alone. B) hares and lynx are so mutually dependent that each species cannot survive without the other. C) multiple biotic and abiotic factors contribute to the cycling of the hare and lynx populations. D) both hare and lynx populations are regulated mainly by abiotic factors. E) the hare population is r-selected and the lynx population is K-selected.
Answer: C
72 A newspaper ad for a local toy store indicates that a very inexpensive microscope available for a small child is able to magnify specimens nearly as much as the much more costly microscope available in your college lab. What is the primary reason for the price difference? A) The ad agency is misrepresenting the ability of the toy microscope to magnify. B) The toy microscope does not have the same fine control for focus of the specimen. C) The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images. D) The college microscope produces greater contrast in the specimens. E) The toy microscope usually uses a different wavelength of light source.
Answer: C
72 card image 72) Hair cells are found in structures represented by numbers A) 1 and 2. B) 3 and 4. C) 5 and 7. D) 6 and 8. E) 9 and 10.
Answer: C
73 73) If the direction of Earth's rotation reversed, the most predictable effect would be A) no more night and day. B) a big change in the length of the year. C) winds blowing from west to east along the equator. D) a loss of seasonal variation at high latitudes. E) the elimination of ocean currents.
Answer: C
73 A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. What is substance X? A) a coenzyme B) an allosteric inhibitor C) a substrate D) an intermediate E) the product
Answer: C
73 A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure? A) full-spectrum white light B) green light C) a mixture of blue and red light D) yellow light E) UV light
Answer: C
74 74) One difference between cancer cells and normal cells is that cancer cells A) are unable to synthesize DNA. B) are arrested at the S phase of the cell cycle. C) continue to divide even when they are tightly packed together. D) cannot function properly because they are affected by density-dependent inhibition. E) are always in the M phase of the cell cycle.
Answer: C
74 74) Which of the following organisms is incorrectly paired with its trophic level? A) cyanobacteriumprimary producer B) grasshopperprimary consumer C) zooplanktonprimary producer D) eagletertiary consumer E) fungusdetritivore
Answer: C
80 Which of the following statements correctly describes any chemical reaction that has reached equilibrium? A) The concentrations of products and reactants are equal. B) The reaction is now irreversible. C) Both forward and reverse reactions have halted. D) The rates of the forward and reverse reactions are equal. E) No reactants remain.
Answer: D
81 Which process is most directly driven by light energy? A) creation of a pH gradient by pumping protons across the thylakoid membrane B) carbon fixation in the stroma C) reduction of NADP⁺ molecules D) removal of electrons from chlorophyll molecules E) ATP synthesis
Answer: D
74 A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water-equal to the volume of blood lost-is transferred directly into one of his veins. What will be the most probable result of this transfusion? A) It will have no unfavorable effect as long as the water is free of viruses and bacteria. B) The patient's red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells. C) The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells. D) The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells. E) The patient's red blood cells will burst because the blood fluid has become hypertonic compared to the cells.
Answer: C
75 75) Food chains are sometimes short because A) only a single species of herbivore feeds on each plant species. B) local extinction of a species causes extinction of the other species in its food chain. C) most of the energy in a trophic level is lost as it passes to the next higher level. D) predator species tend to be less diverse and less abundant than prey species. E) most producers are inedible.
Answer: C
75 75) The decline of MPF activity at the end of mitosis is due to A) the destruction of the protein kinase Cdk. B) decreased synthesis of Cdk. C) the degradation of cyclin. D) the accumulation of cyclin. E) synthesis of DNA.
Answer: C
75 75) The observation that members of a population are uniformly distributed suggests that A) the size of the area occupied by the population is increasing. B) resources are distributed unevenly. C) the members of the population are competing for access to a resource. D) the members of the population are neither attracted to nor repelled by one another. E) the density of the population is low.
Answer: C
75 group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone? A) a compound with the same number of carbon atoms as the hormone B) a compound with the same molecular mass (measured in daltons) as the hormone C) a compound with the same three-dimensional shape as part of the hormone D) a compound with the same number of orbital electrons as the hormone E) a compound with the same number of hydrogen and nitrogen atoms as the hormone
Answer: C
82 82) Although some sharks close their eyes just before they bite, their bites are on target. Researchers have noted that sharks often misdirect their bites at metal objects and that they can find batteries buried under sand. This evidence suggests that sharks keep track of their prey during the split second before they bite in the same way that A) a rattlesnake finds a mouse in its burrow. B) a male silkworm moth locates a mate. C) a bat finds moths in the dark. D) a platypus locates its prey in a muddy river. E) a flatworm avoids light places.
Answer: D
76 card image 76) According to the logistic growth equation SEE IMAGE A) the number of individuals added per unit time is greatest when N is close to zero. B) the per capita growth rate (r) increases as N approaches K. C) population growth is zero when N equals K. D) the population grows exponentially when K is small. E) the birth rate (b) approaches zero as N approaches K.
Answer: C
76 card image Which of the following statements is true regarding the molecule illustrated in Figure 5.3? A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis. C) Molecules of this type are usually liquid at room temperature. D) It is a saturated fatty acid and a diet rich in this molecule may contribute to atherosclerosis. E) It is a saturated fatty acid, a diet rich in this molecule may contribute to atherosclerosis, and molecules of this type are usually liquid at room temperature.
Answer: C
83 card image The structure depicted in Figure 5.7 shows the A) 1-4 linkage of the α glucose monomers of starch. B) 1-4 linkage of the β glucose monomers of cellulose. C) double-helical structure of a DNA molecule. D) α helix secondary structure of a polypeptide. E) β pleated sheet secondary structure of a polypeptide.
Answer: D
77 According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly A) spread in a continuous layer over the inner and outer surfaces of the membrane. B) confined to the hydrophobic interior of the membrane. C) embedded in a lipid bilayer. D) randomly oriented in the membrane, with no fixed inside-outside polarity. E) free to depart from the fluid membrane and dissolve in the surrounding solution.
Answer: C
77 How is photosynthesis similar in C₄ plants and CAM plants? A) In both cases, only photosystem I is used. B) Both types of plants make sugar without the Calvin cycle. C) In both cases, rubisco is not used to fix carbon initially. D) Both types of plants make most of their sugar in the dark. E) In both cases, thylakoids are not involved in photosynthesis.
Answer: C
78 78) Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem? A) the ecosystem's rate of primary production B) the production efficiency of the ecosystem's consumers C) the rate of decomposition in the ecosystem D) the trophic efficiency of the ecosystem E) the location of the nutrient reservoirs in the ecosystem
Answer: C
79 Some bacteria are metabolically active in hot springs because A) they are able to maintain a lower internal temperature. B) high temperatures make catalysis unnecessary. C) their enzymes have high optimal temperatures. D) their enzymes are completely insensitive to temperature. E) they use molecules other than proteins or RNAs as their main catalysts.
Answer: C
79 Which of the following does not occur during the Calvin cycle? A) carbon fixation B) oxidation of NADPH C) release of oxygen D) regeneration of the CO₂ acceptor E) consumption of ATP
Answer: C
8 8) Choose the correct sequence of the following events leading to the sensory processing of a stimulus. 1. transmission 2. transduction 3. integration 4. amplification A) 1 → 2 → 3 → 4 B) 1 → 4 → 2 → 3 C) 2 → 4 → 1 → 3 D) 3 → 1 → 2 → 4 E) 3 → 1 → 4 → 2
Answer: C
8 8) Which of the following is an example of Batesian mimicry? A) an insect that resembles a twig B) a butterfly that resembles a leaf C) a nonvenomous snake that looks like a venomous snake D) a fawn with fur coloring that camouflages it in the forest environment E) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish
Answer: C
8 8) Which of the following is true of a species that has a chromosome number of 2n = 16? A) The species is diploid with 32 chromosomes per cell. B) The species has 16 sets of chromosomes per cell. C) Each cell has eight homologous pairs. D) During the S phase of the cell cycle there will be 32 separate chromosomes. E) A gamete from this species has four chromosomes.
Answer: C
80 Which cell would be best for studying lyosomes? A) muscle cell B) nerve cell C) phagocytic white blood cell D) leaf cell of a plant E) bacterial cell
Answer: C
82 The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound: A) HS B) HS₂ C) H₂S D) H₃S₂ E) H₄S
Answer: C
82 card image In which step in Figure 9.1 is an inorganic phosphate added to the reactant? A) A B) B C) C D) D E) E
Answer: C
85 [SEE IMAGE FOR CARD #84] Which of the following combinations could be linked together to form a nucleotide? A) 1, 2, and 11 B) 3, 7, and 8 C) 5, 9, and 10 D) 11, 12, and 13 E) 12, 14, and 15
Answer: D
87 [SEE IMAGE FOR CARD #84] Which molecule is glycerol? A) 1 B) 6 C) 10 D) 14 E) 15
Answer: C
89 card image If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in Figure 9.2? A) There will be no change in the levels of oxaloacetate and citric acid. B) Oxaloacetate will decrease and citric acid will accumulate. C) Oxaloacetate will accumulate and citric acid will decrease. D) Both oxaloacetate and citric acid will decrease. E) Both oxaloacetate and citric acid will accumulate.
Answer: C
9 9) A chemical produced by an animal that serves as a communication to another animal of the same species is called A) a sign stimulus. B) an inducer. C) a pheromone. D) an imprinter. E) an agonistic promoter.
Answer: C
9 9) Many homeowners mow their lawns during the summer and collect the clippings, which are then hauled to the local landfill. Which of the following actions would most benefit the suburban ecosystem? A) Allow sheep to graze the lawn and then collect the sheep's feces to be delivered to the landfill. B) Collect the lawn clippings and burn them. C) Collect the lawn clippings and add them to a compost pile, don't collect the clippings and let them decompose into the lawn, or apply composted clippings to the lawn. D) Collect the clippings and wash them into the nearest storm sewer that feeds into the local lake. E) Dig up the lawn and cover the yard with asphalt.
Answer: C
9 In order for a protein to be an integral membrane protein it would have to be A) hydrophilic. B) hydrophobic. C) amphipathic, with at least one hydrophobic region. D) completely covered with phospholipids. E) exposed on only one surface of the membrane.
Answer: C
9 Prokaryotic and eukaryotic cells generally have which of the following features in common? A) a membrane-bounded nucleus B) a cell wall made of cellulose C) ribosomes D) flagella or cilia that contain microtubules E) linear chromosomes made of DNA and protein
Answer: C
92 [SEE IMAGE FOR CARD #84] Which of the following molecules could be joined together by a peptide bond as a result of a dehydration reaction? A) 2 and 3 B) 3 and 7 C) 7 and 8 D) 8 and 9 E) 12 and 13
Answer: C
95 card image What happens at the end of the chain in Figure 9.3? A) 2 electrons combine with a proton and a molecule of NAD⁺. B) 2 electrons combine with a molecule of oxygen and two hydrogen atoms. C) 4 electrons combine with a molecule of oxygen and 4 protons. D) 4 electrons combine with four hydrogen and two oxygen atoms. E) 1 electron combines with a molecule of oxygen and a hydrogen atom.
Answer: C
97 In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO₂, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A. Why is coenzyme A, a sulfur-containing molecule derived from a B vitamin, added? A) because sulfur is needed for the molecule to enter the mitochondrion B) in order to utilize this portion of a B vitamin which would otherwise be a waste product from another pathway C) to provide a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle D) because it drives the reaction that regenerates NAD⁺ E) in order to remove one molecule of CO₂
Answer: C
The element present in all organic molecules is A) hydrogen. B) oxygen. C) carbon. D) nitrogen. E) phosphorus.
Answer: C
9 9) Which of the following groups is most threatened by global extinctions? A) mammals B) birds C) fish D) amphibians E) plants
Answer: D
When biologists wish to study the internal ultrastructure of cells, they can achieve the finest resolution by using A) a phase-contrast light microscope. B) a scanning electron microscope. C) a transmission electronic microscope. D) a confocal fluorescence microscope. E) a super-resolution fluorescence microscope.
Answer: C
and the arrangement of carbon, hydrogen, and oxygen atoms.
Answer: C
but as more crystals are added, the crystals will begin to dissolve faster and faster.
Answer: C
deductive
Answer: C
hypotheses are often falsified.
Answer: C
ionic bonds involve the sharing of electrons between atoms.
Answer: C
lack of chloride transport still reduces osmotic potential and decreases the airway surface liquid volume.
Answer: C
therefore, alarm calls are useless.
Answer: C
they are relatively cool. C) temperature is usually uniform throughout a cell. D) heat can never be used to do work. E) heat must remain constant during work.
Answer: C
1 About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? A) carbon, sodium, hydrogen, nitrogen B) carbon, oxygen, phosphorus, hydrogen C) oxygen, hydrogen, calcium, nitrogen D) carbon, hydrogen, nitrogen, oxygen E) carbon, oxygen, nitrogen, calcium
Answer: D
9 The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius? A) 0.2°C B) 1.0°C C) 2.0°C D) 10.0°C E) 20.0°C
Answer: D
9 When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway? A) receptor B) relay molecule C) transducer D) signal molecule E) endocrine molecule
Answer: D
1) Which of the following statements is consistent with the principle of competitive exclusion? A) Bird species generally do not compete for nesting sites. B) The random distribution of one competing species will have a positive impact on the population growth of the other competing species. C) Two species with the same fundamental niche will exclude other competing species. D) Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species. E) Natural selection tends to increase competition between related species.
Answer: D
10 10) To better comprehend the magnitude of current extinctions, it will be necessary to A) monitor atmospheric carbon dioxide levels more closely. B) differentiate between plant extinction and animal extinction numbers. C) focus on identifying more species of mammals and birds. D) identify more of the yet unknown species of organisms on Earth. E) use the average extinction rates of vertebrates as a baseline.
Answer: D
10 10) Which of these statements is false? A) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. B) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY). C) Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. E) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization.
Answer: D
10 How many electron pairs does carbon share in order to complete its valence shell? A) 1 B) 2 C) 3 D) 4 E) 8
Answer: D
10 When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are A) peripheral proteins. B) phospholipids. C) carbohydrates. D) integral proteins. E) cholesterol molecules.
Answer: D
103 Which of the following categories includes all others in the list? A) monosaccharide B) disaccharide C) starch D) carbohydrate E) polysaccharide
Answer: D
11 11) The muscle spindle is A) an actin-myosin complex. B) a troponin-tropomyosin complex. C) axons wound around muscle fibers. D) a group of dendrite-encircled muscle fibers. E) a muscle cell that makes up a muscle group.
Answer: D
11 Which of the following is an example of potential rather than kinetic energy? A) the muscle contractions of a person mowing grass B) water rushing over Niagara Falls C) light flashes emitted by a firefly D) a molecule of glucose E) the flight of an insect foraging for food
Answer: D
11 Which type of bond must be broken for water to vaporize? A) ionic bonds B) both hydrogen bonds and ionic bonds C) polar covalent bonds D) hydrogen bonds E) both polar covalent bonds and hydrogen bonds
Answer: D
70 card image In the methane molecule shown in the figure above, bonds have formed that include both the s orbital valence electrons of the hydrogen atoms and the p orbital valence electrons of the carbon. The electron orbitals in these bonds are said to be A) double orbitals. B) tetrahedral orbitals. C) complex orbitals. D) hybrid orbitals. E) polar orbitals.
Answer: D 71 card image Which one of the atoms shown would be most likely to form a cation with a charge of +1? [SEE IMAGE FOR CHOICES] Answer: A 72 card image Which one of the atoms shown would be most likely to form an anion with a charge of -1? [SEE IMAGE FOR CHOICES] Answer: D 73 card image Which of the following pairs of atoms would be most likely to form a polar covalent bond? [SEE IMAGE FOR CHOICES] Answer: A 74 card image Which of the following pairs of atoms would be most likely to form an ionic bond? [SEE IMAGE FOR CHOICES] Answer: B
1 If photosynthesizing green algae are provided with CO₂ synthesized with heavy oxygen (¹⁸O), later analysis will show that all but one of the following compounds produced by the algae contain the ¹⁸O label. That one is A) 3-phosphoglycerate. B) glyceraldehyde 3-phosphate (G3P). C) glucose. D) ribulose bisphosphate (RuBP). E) O₂.
Answer: E
1 Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? A) catalysis B) metabolism C) anabolism D) dehydration E) catabolism
Answer: E
1) "How do seed-eating animals affect the distribution and abundance of the trees?" This question A) would require an elaborate experimental design to answer. B) would be difficult to answer because a large experimental area would be required. C) would be difficult to answer because a long-term experiment would be required. D) is one that a present-day ecologist would be likely to ask. E) All options are correct.
Answer: E
10 10) Which of the following is an example of an ecosystem? A) All of the brook trout in a 500 hectare² river drainage system. B) The plants, animals, and decomposers that inhabit an alpine meadow. C) A pond and all of the plant and animal species that live in it. D) The intricate interactions of the various plant and animal species on a savanna during a drought. E) Interactions between all of the organisms and their physical environment in a tropical rain forest.
Answer: E
10 Prokaryotes are classified as belonging to two different domains. What are the domains? A) Bacteria and Eukarya B) Archaea and Monera C) Eukarya and Monera D) Bacteria and Protista E) Bacteria and Archaea
Answer: E
105 What is the oxidizing agent in the following reaction? Pyruvate + NADH + H⁺ → Lactate + NAD⁺ A) oxygen B) NADH C) NAD⁺ D) lactate E) pyruvate
Answer: E
11 A mycoplasma is an organism with a diameter between 0.1 and 1.0 µm. What does the organism's size tell you about how it might be classified? A) It must be a single-celled protist. B) It must be a single-celled fungus. C) It could be almost any typical bacterium. D) It could be a typical virus. E) It could be a very small bacterium.
Answer: E
11 Which of the events listed below occurs in the light reactions of photosynthesis? A) NADP is produced. B) NADPH is reduced to NADP⁺. C) Carbon dioxide is incorporated into PGA. D) ATP is phosphorylated to yield ADP. E) Light is absorbed and funneled to reaction-center chlorophyll a.
Answer: E
12 12) We should care about loss in biodiversity in the populations of other species because of A) biophilia. B) potential loss of medicines and other products yet undiscovered from threatened species. C) potential loss of genes, some of which may code for proteins useful to humans. D) the risk to global ecological stability. E) All of the options are correct.
Answer: E
12 12) Which of the following would be most significant in understanding the structure of an ecological community? A) determining how many species are present overall B) determining which particular species are present C) determining the kinds of interactions that occur among organisms of different species D) determining the relative abundance of species E) determining how many species are present overall, which particular species are present, the kinds of interactions that occur among organisms of different species, and the relative abundance of species
Answer: E
12 Which of the following statements best describes the carbon atoms present in a seed-eating bird? A) They were incorporated into organic molecules by plants. B) They were processed into sugars through photosynthesis. C) They are ultimately derived from carbon dioxide. D) They were incorporated into organic molecules by plants, and they are ultimately derived from carbon dioxide. E) They were incorporated into organic molecules by plants, they were processed into sugars through photosynthesis, and they are ultimately derived from carbon dioxide.
Answer: E
13 13) The karyotype of one species of primate has 48 chromosomes. In a particular female, cell division goes awry and she produces one of her eggs with an extra chromosome (25). The most probable source of this error would be a mistake in which of the following? A) mitosis in her ovary B) metaphase I of one meiotic event C) telophase II of one meiotic event D) telophase I of one meiotic event E) either anaphase I or II
Answer: E
13 13) Which of the following studies would a community ecologist undertake to learn about competitive interactions? A) selectivity of nest sites among cavity-nesting songbirds B) the grass species preferred by grazing pronghorn antelope and bison C) nitrate and phosphate uptake by various hardwood forest tree species D) stomach analysis of brown trout and brook trout in streams where they coexist E) selectivity of nest sites among cavity-nesting songbirds, the grass species preferred by grazing pronghorn antelope and bison, nitrate and phosphate uptake by various hardwood forest tree species, and stomach analysis of brown trout and brook trout in streams where they coexist
Answer: E
13 The primary function of polysaccharides attached to the glycoproteins and glycolipids of animal cell membranes is A) to facilitate diffusion of molecules down their concentration gradients. B) to actively transport molecules against their concentration gradients. C) to maintain the integrity of a fluid mosaic membrane. D) to maintain membrane fluidity at low temperatures. E) to mediate cell-to-cell recognition.
Answer: E
14 14) A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? A) It must be human. B) It must be a primate. C) It must be an animal. D) It must be sexually reproducing. E) Its gametes must have 23 chromosomes.
Answer: E
14 14) Animals use pheromones to communicate A) reproductive readiness. B) species recognition. C) gender recognition. D) danger. E) All options are correct.
Answer: E
14 14) Imagine some cosmic catastrophe jolts Earth so that its axis is perpendicular to the orbital plane between Earth and the sun. The most obvious effect of this change would be A) the elimination of tides. B) an increase in the length of night. C) an increase in the length of a year. D) a decrease in temperature at the equator. E) the elimination of seasonal variation.
Answer: E
14 14) Which of the following choices would most likely promote random distribution? A) territorial species B) species that secrete chemicals to attract or inhibit other individuals C) flocking and schooling behaviors D) spacing during the breeding season E) homogeneous chemical and physical factors in the environment
Answer: E
15 A system at chemical equilibrium A) consumes energy at a steady rate. B) releases energy at a steady rate. C) consumes or releases energy, depending on whether it is exergonic or endergonic. D) has zero kinetic energy. E) can do no work.
Answer: E
15 Because most receptors are membrane proteins, which of the following is usually true? A) They lead to changes in intracellular ion concentration. B) They open and close in response to protein signals. C) They are only attached to one membrane surface: exterior or interior. D) They preferentially bind with lipid or glycolipid signal molecules. E) They change their conformation after binding with signal polypeptides.
Answer: E
15 Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis? A) 0% B) 2% C) 10% D) 38% E) 100%
Answer: E
15 Which of the following is (are) true of natural selection? A) It requires genetic variation. B) It results in descent with modification. C) It involves differential reproductive success. D) It results in descent with modification and involves differential reproductive success. E) It requires genetic variation, results in descent with modification, and involves differential reproductive success.
Answer: E
16 16) Prairie dogs once covered the expanses of the Great Plains. Their grazing made the grass more nutritious for the huge herds of bison, and they were preyed upon by a variety of snakes, raptors, and mammals. In fact, the black-footed ferret (now endangered) specialized in prairie dog predation. Today, increases in housing and agricultural developments have eradicated many prairie dog towns. Which of the following statements about prairie dogs is true? A) Their realized niche has expanded. B) They have a competitive relationship with bison. C) They are probably a poor candidate for keystone species. D) Their fundamental niche has been compromised. E) Their fundamental niche has expanded.
Answer: E
16 One mole (mol) of glucose (molecular mass = 180 daltons) is A) 180 × 10²³ molecules of glucose. B) 1 kg of glucose dissolved in 1 L of solution. C) the largest amount of glucose that can be dissolved in 1 L of solution. D) 180 kilograms of glucose. E) both 180 grams of glucose and 6.02 × 10²³ molecules of glucose.
Answer: E
17 17) Which of the following is the most important assumption for the capture-recapture method to estimate the size of wildlife populations? A) All females in the population have the same litter size. B) More individuals emigrate from, as opposed to immigrate into, a population. C) Over 50% of the marked individuals need to be trapped during the recapture phase. D) There is a 50:50 ratio of males to females in the population before and after trapping and recapture. E) Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.
Answer: E
18 18) How might an ecologist test whether a species is occupying its realized or its fundamental niche? A) Study the temperature range and humidity requirements of the species. B) Observe if the niche size changes after the addition of nutritional resources to the habitat. C) Observe if the niche size changes after the introduction of a similar non-native species. D) Measure the change in reproductive success when the species is subjected to environmental stress. E) Remove a competitor species to see if the species expands its range.
Answer: E
19 From its atomic number of 15, it is possible to predict that the phosphorus atom has A) 15 neutrons. B) 15 protons. C) 15 electrons. D) 8 electrons in its outermost electron shell. E) 15 protons and 15 electrons.
Answer: E
19 Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question. A. operant conditioning B. agonistic behavior C. innate behavior D. imprinting E. altruistic behavior 19) Upon observing a golden eagle flying overhead, a sentry prairie dog gives a warning call to other foraging members of the prairie dog community. A) A B) B C) C D) D E) E
Answer: E
2 Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? A) CO₂ and glucose B) H₂O and O₂ C) ADP, Pi, and NADP⁺ D) electrons and H⁺ E) ATP and NADPH
Answer: E
20 Atoms whose outer electron shells contain 8 electrons tend to A) form ions in aqueous solutions. B) form hydrogen bonds in aqueous solutions. C) be stable and chemically nonreactive, or inert. D) be gaseous at room temperature. E) be both chemically inert and gaseous at room temperature.
Answer: E
20 Organic molecules with only hydrogens and five carbon atoms can have different structures in all of the following ways except A) by branching of the carbon skeleton. B) by varying the number of double bonds between carbon atoms. C) by varying the position of double bonds between carbon atoms. D) by forming a ring. E) by forming enantiomers.
Answer: E
20 Recent evidence shows that when chromosomes decondense during interphase, their DNA molecules do not intermingle. Instead, they occupy distinct territories within the nucleus. Considering the structure and location of the following structures, which is most likely to be involved in chromosome location? A) nuclear pores B) the nucleolus C) microfilaments D) the nuclear lamina E) the nuclear matrix
Answer: E
20 Sutherland discovered that epinephrine signals A) a decrease in levels of cAMP as a result of bypassing the plasma membrane. B) lower blood glucose by binding to liver cells. C) interactions with insulin inside muscle cells. D) interactions directly with glycogen phosphorylase. E) elevation of cytosolic concentrations of cyclic AMP.
Answer: E
22 You have a freshly prepared 0.1 M solution of glucose in water. Each liter of this solution contains how many glucose molecules? A) 6.02 × 10²³ B) 3.01 × 10²³ C) 6.02 × 10²⁴ D) 12.04 × 10²³ E) 6.02 × 10²²
Answer: E
23 Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins? A) G protein-coupled receptor signaling B) ligand-gated ion channel signaling C) adenylyl cyclase activity D) phosphatase activity E) receptor tyrosine kinase activity
Answer: E
23 Why is glycolysis described as having an investment phase and a payoff phase? A) It both splits molecules and assembles molecules. B) It attaches and detaches phosphate groups. C) It uses glucose and generates pyruvate. D) It shifts molecules from cytosol to mitochondrion. E) It uses stored ATP and then forms a net increase in ATP.
Answer: E
24 The Golgi apparatus has a polarity or sidedness to its structure and function. Which of the following statements correctly describes this polarity? A) Transport vesicles fuse with one side of the Golgi and leave from the opposite side. B) Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. C) Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. D) Soluble proteins in the cisternae (interior) of the Golgi may be sorted and modified as they move from one side of the Golgi to the other. E) All of the above correctly describe polar characteristics of the Golgi function.
Answer: E
24 When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanation for this observation? A) Cells are open systems, but a test tube is a closed system. B) Cells are less efficient at heat production than nonliving systems. C) The hydrolysis of ATP in a cell produces different chemical products than does the reaction in a test tube. D) The reaction in cells must be catalyzed by enzymes, but the reaction in a test tube does not need enzymes. E) Reactant and product concentrations in the test tube are different from those in the cell.
Answer: E
24 Which of the following categories of organisms is least likely to be revised? A) kingdom B) class C) order D) phylum E) species
Answer: E
24 You have a freshly prepared 1 M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample? A) 6.02 × 10²³ B) 3.01 × 10²³ C) 6.02 × 10²⁴ D) 12.04 × 10²³ E) 6.02 × 10²²
Answer: E
26 26) A type of bird similar to a chickadee learns to peck through the cardboard tops of milk bottles left on doorsteps to obtain the desired cream from the top. What term best applies to this behavior? A) sign stimulus B) cognition C) imprinting D) classical conditioning E) operant conditioning
Answer: E
26 Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? A) NaCl B) HCl C) NH₃ D) H₂CO₃ E) NaOH
Answer: E
27 27) What is the limiting factor for the growth of trees in the tundra? A) low precipitation B) cold temperatures C) insufficient minerals in bedrock D) pH of soils E) permafrost
Answer: E
28 28) Chromatids are separated from each other. A) The statement is true for mitosis only. B) The statement is true for meiosis I only. C) The statement is true for meiosis II only. D) The statement is true for mitosis and meiosis I. E) The statement is true for mitosis and meiosis II.
Answer: E
28 28) If the sex ratio in a population is significantly different from 50:50, then which of the following will always be true? A) The population will enter the extinction vortex. B) The genetic variation in the population will increase over time. C) The genetic variation in the population will decrease over time. D) The effective population size will be greater than the actual population size. E) The effective population size will be less than the actual population size.
Answer: E
29 29) Which of the following life history traits can potentially influence effective population size (Ne)? A) maturation age B) genetic relatedness among individuals in a population C) family and population size D) gene flow between geographically separated populations E) All of the options are correct.
Answer: E
29 A solution contains 0.0000001(10⁻⁷) moles of hydroxyl ions [OH⁻] per liter. Which of the following best describes this solution? A) acidic: H⁺ acceptor B) basic: H⁺ acceptor C) acidic: H⁺ donor D) basic: H⁺ donor E) neutral
Answer: E
29 Water passes quickly through cell membranes because A) the bilayer is hydrophilic. B) it moves through hydrophobic channels. C) water movement is tied to ATP hydrolysis. D) it is a small, polar, charged molecule. E) it moves through aquaporins in the membrane.
Answer: E
3 Photosynthesis is not responsible for A) oxygen in the atmosphere. B) the ozone layer. C) most of the organic carbon on Earth's surface. D) atmospheric CO₂. E) fossil fuels.
Answer: E
3 The experimental approach taken in current biological investigations presumes that A) simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms. B) a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods. C) although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods. D) living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products. E) living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena.
Answer: E
30 What is the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in RNA? A) The sugar molecule is different. B) The nitrogen-containing base is different. C) The number of phosphates is three instead of one. D) The number of phosphates is three instead of two. E) There is no difference.
Answer: E
31 31) Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
Answer: E
31 Which of the following statements is true of signal molecules? A) When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules. B) In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form IP₃ and calcium. C) In most cases, signal molecules interact with the cell at the plasma membrane and then enter the cell and eventually the nucleus. D) Toxins such as those that cause botulism and cholera interfere with the ability of activated G proteins to hydrolyze GTP to GDP, resulting in phosphodiesterase activity in the absence of an appropriate signal molecule. E) Protein kinase A activation is one possible result of signal molecules binding to G protein-coupled receptors.
Answer: E
32 32) According to the nonequilibrium model, A) communities will remain in a climax state if there are no human disturbances. B) community structure remains stable in the absence of interspecific competition. C) communities are assemblages of closely linked species that are irreparably changed by disturbance. D) interspecific interactions induce changes in community composition over time. E) communities are constantly changing after being influenced by disturbances.
Answer: E
32 32) Natural selection involves energetic trade-offs between A) choosing how many offspring to produce over the course of a lifetime and how long to live. B) producing large numbers of gametes when employing internal fertilization versus fewer numbers of gametes when employing external fertilization. C) the emigration of individuals when they are no longer reproductively capable or committing suicide. D) increasing the number of individuals produced during each reproductive episode with a corresponding decrease in parental care. E) high survival rates of offspring and the cost of parental care.
Answer: E
32 32) Some dogs love attention, and Frodo the beagle learns that if he barks, he gets attention. Which of the following might you use to describe this behavior? A) The dog is displaying an instinctive fixed action pattern. B) The dog is performing a social behavior. C) The dog is trying to protect its territory. D) The dog has been classically conditioned. E) The dog's behavior is a result of operant conditioning.
Answer: E
32 32) The amount of chemical energy in consumers' food that is converted to their own new biomass during a given time period is known as which of the following? A) biomass B) standing crop C) biomagnification D) primary production E) secondary production
Answer: E
33 Dehydration reactions are used in forming which of the following compounds? A) triacylglycerides B) polysaccharides C) proteins D) triacylglycerides and proteins only E) triacylglycerides, polysaccharides, and proteins
Answer: E
33 card image The two molecules shown in the figure above are best described as A) enantiomers. B) radioactive isotopes. C) structural isomers. D) nonisotopic isomers. E) cis-trans isomers.
Answer: E
34 34) A rod exposed to light will A) fire action potentials that will increase its release of glutamate. B) undergo a graded depolarization that will increase its release of glutamate. C) undergo a graded hyperpolarization that will increase its release of glutamate. D) undergo a graded depolarization that will decrease its release of glutamate. E) undergo a graded hyperpolarization that will decrease its release of glutamate.
Answer: E
34 34) Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called A) ATPases. B) kinetochores. C) kinases. D) proton pumps. E) cyclins.
Answer: E
34 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? A) NAD+ B) NADH C) ATP D) ADP + Pi E) FADH2
Answer: E
34 When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? A) The cell will burst. B) The cell membrane will lyse. C) Plasmolysis will shrink the interior. D) The cell will become flaccid. E) The cell will become turgid.
Answer: E
34 Why is it important that an experiment include a control group? A) The control group is the group that the researcher is in control of, the group in which the researcher predetermines the results. B) The control group provides a reserve of experimental subjects. C) A control group is required for the development of an "If...then" statement. D) A control group assures that an experiment will be repeatable. E) Without a control group, there is no basis for knowing if a particular result is due to the variable being tested.
Answer: E
35 35) Pacific salmon and annual plants are excellent examples of A) cohort disintegration. B) dispersion. C) Allee effect. D) iteroparous reproduction. E) semelparous reproduction.
Answer: E
35 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered in components of the electron transport chain. What do they do? A) donate electrons B) act as reducing agents C) act as oxidizing agents D) transport protons within the mitochondria and chloroplasts E) both oxidize and reduce during electron transport
Answer: E
35 What aspects of protein structure are stabilized or assisted by hydrogen bonds? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure E) secondary, tertiary, and quaternary structures, but not primary structure
Answer: E
36 36) A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation? A) The cell would prematurely enter anaphase. B) The cell would never leave metaphase. C) The cell would never enter metaphase. D) The cell would never enter prophase. E) The cell would undergo normal mitosis, but fail to enter the next G₁ phase.
Answer: E
36 How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids? A) 4¹² B) 12²⁰ C) 240 D) 20 E) 20¹²
Answer: E
36 Inside an active mitochondrion, most electrons follow which pathway? A) glycolysis → NADH → oxidative phosphorylation → ATP → oxygen B) citric acid cycle → FADH₂ → electron transport chain → ATP C) electron transport chain → citric acid cycle → ATP → oxygen D) pyruvate → citric acid cycle → ATP → NADH → oxygen E) citric acid cycle → NADH → electron transport chain → oxygen
Answer: E
36 The function of phosphatases in signal transduction is best described as to A) move the phosphate group of the transduction pathway to the next molecule of a series. B) prevent a protein kinase from being reused when there is another extracellular signal. C) amplify the transduction signal so it affects multiple transducers. D) amplify the second messengers such as cAMP. E) inactivate protein kinases and turn off the signal transduction.
Answer: E
36 The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane-more acidic outside the cell than inside the cell. Phosphate transport is an example of A) passive diffusion. B) facilitated diffusion. C) active transport. D) osmosis. E) cotransport.
Answer: E
36 Which animal cell organelle contains enzymes that transfer hydrogen from various substrates to oxygen? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome
Answer: E
37 37) To visualize and identify meiotic cells at metaphase with a microscope, what would you look for? A) sister chromatids grouped at the poles B) individual chromosomes all at the cell's center C) an uninterrupted spindle array D) the synaptonemal complex E) tetrads all aligned at the cell's center
Answer: E
37 37) Why does a vegetarian leave a smaller ecological footprint than an omnivore? A) Fewer animals are slaughtered for human consumption. B) There is an excess of plant biomass in all terrestrial ecosystems. C) Vegetarians need to ingest less chemical energy than omnivores. D) Vegetarians require less protein than do omnivores. E) Eating meat is an inefficient way of acquiring photosynthetic productivity.
Answer: E
37 Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells? A) simple diffusion B) phagocytosis C) active transport pumps D) exocytosis E) facilitated diffusion
Answer: E
37 One liter of a solution of pH 9 has how many more hydroxyl ions (OH⁻) than 1 L of a solution of pH 4? A) 5 times more B) 32 times more C) 50,000 times more D) 10,000 times more E) 100,000 times more
Answer: E
39 39) Which of the following describe(s) cyclin-dependent kinase (Cdk)? A) Cdk is inactive, or "turned off," in the presence of cyclin. B) Cdk is present throughout the cell cycle. C) Cdk is an enzyme that attaches phosphate groups to other proteins. D) Cdk is inactive, or "turned off," in the presence of cyclin and it is present throughout the cell cycle. E) Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other proteins.
Answer: E
39 39) Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems? A) Many primary and higher-order consumers are opportunistic feeders. B) Decomposers compete with higher-order consumers for nutrients and energy. C) Nutrient cycles involve both abiotic and biotic components of ecosystems. D) Nutrient cycling rates tend to be limited by decomposition. E) Energy transfer between tropic levels is in almost all cases less than 20% efficient.
Answer: E
39 Buffers are substances that help resist shifts in pH by A) releasing H⁺ to a solution when acids are added. B) donating H⁺ to a solution when bases are added. C) releasing OH⁻ to a solution when bases are added. D) accepting H⁺ from a solution when acids are added. E) both donating H⁺ to a solution when bases are added, and accepting H⁺ when acids are added.
Answer: E
4 4) As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap, the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory and isolate the two different species, you discover that the offspring of both species are found to be nocturnal. You have discovered an example of A) mutualism. B) character displacement. C) Batesian mimicry. D) facultative commensalism. E) resource partitioning.
Answer: E
4 Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H₂S A) will ionize more readily. B) will have greater cohesion to other molecules of H₂S. C) will have a greater tendency to form hydrogen bonds with each other. D) will have a higher capacity to absorb heat for the same change in temperature. E) will not form hydrogen bonds with each other.
Answer: E
4 What factors are most important in determining which elements are most common in living matter? A) the relative abundances of the elements in Earth's crust and atmosphere B) the emergent properties of the simple compounds made from these elements C) the reactivity of the elements with water D) the chemical stability of the elements E) both the relative abundances of the elements and the emergent properties of the compounds made from these elements
Answer: E
40 For the following question, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II 40) Centromeres of sister chromatids disjoin and chromatids separate. A) II B) III C) IV D) V E) VII
Answer: E
40 Given the cooperativity of science, which of the following is most likely to result in an investigator being intellectually looked down upon by other scientists? A) Making money as the result of studies in which a new medication is discovered. B) Doing meticulous experiments that show data that contradict what has been previously reported by the scientific community. C) Spending most of a lifetime investigating a small and seemingly unimportant organism. D) Getting negative results from the same set of experiments. E) Being found to have falsified or created data to better fit a hypothesis.
Answer: E
41 41) A ligand for the umami receptor in the sense of taste is A) glucose. B) sodium ions. C) potassium ions. D) hydrogen ions. E) monosodium glutamate.
Answer: E
41 41) Feeding behavior with a high energy intake-to-expenditure ratio is called A) herbivory. B) autotrophy. C) heterotrophy. D) search scavenging. E) optimal foraging.
Answer: E
41 The amino acids of the protein keratin are arranged predominantly in an α helix. This secondary structure is stabilized by A) covalent bonds. B) peptide bonds. C) ionic bonds. D) polar bonds. E) hydrogen bonds.
Answer: E
41 What is the primary function of the Calvin cycle? A) use ATP to release carbon dioxide B) use NADPH to release carbon dioxide C) split water and release oxygen D) transport RuBP out of the chloroplast E) synthesize simple sugars from carbon dioxide
Answer: E
41 Which of the following is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal? A) The sodium ions are moving down their electrochemical gradient while glucose is moving up. B) Glucose entering the cell along its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient. C) Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. D) The cotransporter can also transport potassium ions. E) A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.
Answer: E
43 43) The contraction of skeletal muscles is based on A) actin filaments coiling up to become shorter. B) myosin filaments coiling up to become shorter. C) actin and myosin filaments both coiling up to become shorter. D) actin cross-bridges binding to myosin and then flexing. E) myosin cross-bridges binding to actin and then flexing.
Answer: E
43 43) Which of the following might affect the foraging behavior of an animal in the context of optimal foraging? A) risk of predation B) prey size C) prey defenses D) prey density E) All of the options are correct.
Answer: E
44 44) Compared to oxidative skeletal muscle fibers, those classified as glycolytic typically have A) a higher concentration of myoglobin. B) a higher density of mitochondria. C) a darker visual appearance. D) a smaller diameter. E) less resistance to fatigue.
Answer: E
44 44) If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true? A) Polar bears can provide more food for humans than seals can. B) The total biomass of the fish is lower than that of the seals. C) Seal meat probably contains the highest concentrations of fat-soluble toxins. D) Seal populations are larger than fish populations. E) The fish can potentially provide more food for humans than the seal meat can.
Answer: E
45 45) Nitrogen is available to plants only in the form of A) N2 in the atmosphere. B) nitrite ions in the soil. C) uric acid from animal excretions. D) amino acids from decomposing plant and animal proteins. E) nitrate ions in the soil.
Answer: E
45 What bonding or interaction is most likely to occur among a broad array of molecules of various types (polar, nonpolar, hydrophilic, hydrophobic)? A) covalent bonding B) polar covalent bonding C) ionic bonding D) hydrogen bonding E) van der Waals interactions
Answer: E
45 Which of the following produces the most ATP when glucose (C₆H₁₂O₆) is completely oxidized to carbon dioxide (CO₂) and water? A) glycolysis B) fermentation C) oxidation of pyruvate to acetyl CoA D) citric acid cycle E) oxidative phosphorylation (chemiosmosis)
Answer: E
45 card image Which functional group(s) shown above is (are) present in all amino acids? A) A and B B) B and D C) C only D) D only E) C and D
Answer: E
46 46) The mating system in which females are more ornamented than males is A) monogamy. B) promiscuity. C) polygamy. D) polygyny. E) polyandry.
Answer: E
47 47) The growing season would generally be shortest in which of the following biomes? A) savanna B) temperate broadleaf forest C) temperate grassland D) tropical rain forest E) coniferous forest
Answer: E
47 47) Which of the following locations is the reservoir for carbon for the carbon cycle? A) atmosphere B) sediments and sedimentary rocks C) fossilized plant and animal remains (coal, oil, and natural gas) D) plant and animal biomass E) all of the above
Answer: E
47 47) Which of the following was the most significant limiting factor in human population growth in the 20th century? A) famine B) non-HIV disease C) HIV D) genocide E) clean water
Answer: E
47 Changing a single amino acid in a protein consisting of 325 amino acids would A) alter the primary structure of the protein, but not its tertiary structure or function. B) cause the tertiary structure of the protein to unfold. C) always alter the biological activity or function of the protein. D) always alter the primary structure of the protein and disrupt its biological activity. E) always alter the primary structure of the protein, sometimes alter the tertiary structure of the protein, and affect its biological activity.
Answer: E
47 Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following? A) antiviral medications that are efficient and work well with all viruses B) antibiotics against the viruses in question C) intravenous feeding techniques D) medication to prevent blood loss E) hydrating drinks that include high concentrations of salts and glucose
Answer: E
47 Which of the following would be regarded as compounds? A) H₂O, O₂, and CH₄ B) H₂O and O₂ C) O₂ and CH₄ D) CH₄ and O₂, but not H₂O E) H₂O and CH₄, but not O₂
Answer: E
47 card image Which of the groups shown above is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules? A) A B) B C) C D) D E) E
Answer: E
48 48) Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be responsible for A) the death of fish in lakes. B) precipitation with a pH as low as 3.0. C) calcium deficiency in soils. D) direct damage to plants by leaching nutrients from the leaves. E) All of the options are correct.
Answer: E
48 48) Trees are not usually found in the tundra biome because of A) insufficient annual precipitation. B) acidic soils. C) extreme winter temperatures. D) overbrowsing by musk ox and caribou. E) permafrost.
Answer: E
48 48) Which of the following statements is true about certainty of paternity? A) Young or eggs laid by a female are likely to contain the same genes as another female's eggs in a population of birds. B) Certainty of paternity is high in most species with internal fertilization because the acts of mating and birth are separated by time. C) Males that guard females they have mated with are certain of their paternity. D) Certainty of paternity is low when egg laying and mating occur together, as in external fertilization. E) Paternal behavior exists because it has been reinforced over generations by natural selection.
Answer: E
48 The students decide that for one of their experiments, they want to see whether the organisms can photosynthesize. Which of the following is the best hypothesis? A) If the Dinobryon can live > 5 days without added food, they must be able to photosynthesize. B) If the Dinobryon can live without exposure to light for > 5 days, they must be able to photosynthesize. C) If the Dinobryon photosynthesize, they must need no other minerals or nutrients and will be able to live in distilled water and light alone. D) If the Dinobryon are kept in the dark, one-half will be expected to die in 5 days. E) If the Dinobryon are able to photosynthesize, the students should be able to extract photosynthetic pigments.
Answer: E
49 What methods may be used to elucidate the structures of purified proteins? A) X-ray crystallography B) bioinformatics C) analysis of amino acid sequence of small fragments D) NMR spectroscopy E) both X-ray crystallography and NMR spectroscopy
Answer: E
5 5) Which of the following defines a genome? A) representation of a complete set of a cell's polypeptides B) the complete set of an organism's polypeptides C) the complete set of a species' polypeptides D) a karyotype E) the complete set of an organism's genes
Answer: E
5 When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that A) the integral membrane proteins are not strong enough to hold the bilayer together. B) water that is present in the middle of the bilayer freezes and is easily fractured. C) hydrophilic interactions between the opposite membrane surfaces are destroyed on freezing. D) the carbon-carbon bonds of the phospholipid tails are easily broken. E) the hydrophobic interactions that hold the membrane together are weakest at this point.
Answer: E
5 Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge? A) ribosomes, nucleus, mitochondria B) chloroplasts, ribosomes, vacuoles C) nucleus, ribosomes, chloroplasts D) vacuoles, ribosomes, nucleus E) nucleus, mitochondria, ribosomes
Answer: E
50 50) For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable? A) It is safe enough to limit all apoptosis. B) It does not alter metabolically active cells. C) It only attacks cells that are density dependent. D) It interferes with cells entering G₀. E) It interferes with rapidly dividing cells.
Answer: E
50 card image 50) Connell conducted this experiment to learn more about A) character displacement in the color of barnacles. B) habitat preference in two different species of barnacles. C) desiccation resistance and barnacle species. D) how sea-level changes affect barnacle distribution. E) competitive exclusion and distribution of barnacle species.
Answer: E
51 51) The fru gene in fruit flies A) controls sex-specific development in the fruit fly. B) is a master regulatory gene that directs expression of many other genes. C) can be genetically manipulated in females so that they will perform male sex behaviors. D) programs males for appropriate courtship behaviors. E) All of the options are correct.
Answer: E
51 51) This is caused by excessive nutrient runoff into aquatic ecosystems. A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: E
51 One idea to mitigate the effects of burning fossil fuels on atmospheric CO₂ concentrations is to pipe liquid CO₂ into the ocean at depths of 2,500 feet or greater. At the high pressures at such depths, CO₂ is heavier than water. What potential effects might result from implementing such a scheme? A) increased photosynthetic carbon fixation because of the increased dissolved carbon dioxide in the deep water B) increased carbonate concentrations in the deep waters C) reduced growth of corals from a change in the carbonate—bicarbonate equilibrium D) no effect because carbon dioxide is not soluble in water E) both increased acidity of the deep waters and changes in the growth of bottom-dwelling organisms with calcium carbonate shells
Answer: E
51 card image 51) According to the Shannon Diversity Index, which block would show the greatest diversity? A) 1 B) 2 C) 3 D) 4 E) 5
Answer: E
51 card image 51) Which curve best describes survivorship in marine molluscs? A) A B) B C) C D) D E) E
Answer: E
51 card image The differences among the three categories of cytoskeletal elements outlined in the table above would suggest that each of the following has specialized roles. Which of the following is a correct match? (All three elements are involved in the maintenance of cell shape.) A) microfilaments and the nuclear lamina B) microtubules and cleavage furrow formation C) microfilaments and ciliary motion D) intermediate filaments and cytoplasmic streaming E) microtubules and chromosome movement
Answer: E
51 card image Which molecule shown above would have a positive charge in aqueous solution at pH 7? A) A B) B C) C D) D E) E
Answer: E
52 card image Use the following diagram of a hypothetical food web to answer the following question. The arrows represent the transfer of food energy between the various trophic levels. Figure 54.3 52) Which letter represents an organism that could be a carnivore? A) A B) B C) C D) D E) E
Answer: E
53 53) In terms of nutrient cycling, why does timber harvesting in a temperate forest cause less ecological devastation than timber harvesting in tropical rain forests? A) Trees are generally less numerous in temperate forests, so fewer nutrients will be removed from the temperate forest ecosystem during a harvest. B) Temperate forest tree species require fewer nutrients to survive than their tropical counterpart species, so a harvest removes fewer nutrients from the temperate ecosystem. C) The warmer temperatures in the tropics influence rain forest species to assimilate nutrients more slowly, so tropical nutrient absorption is much slower than in temperate forests. D) There are far fewer decomposers in tropical rain forests, so turning organic matter into usable nutrients is a slower process than in temperate forest ecosystems. E) Typical harvests remove up to 75% of the nutrients in the woody trunks of tropical rain forest trees, leaving nutrient-impoverished soils behind.
Answer: E
53 card image The lettered circle in Figure 12.1 shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is gray. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages. 53) What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis? A) A B) B C) C D) D E) E
Answer: E
54 54) Skeletal muscle contraction begins when calcium ions bind to A) energized cross-bridges. B) myosin. C) actin. D) tropomyosin. E) troponin.
Answer: E
54 Answer: C Answer: C 55 Which catabolic processes may have been used by cells on ancient Earth before free oxygen became available? A) glycolysis and fermentation only B) glycolysis and the citric acid cycle only C) glycolysis, pyruvate oxidation, and the citric acid cycle D) oxidative phosphorylation only E) glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation, using an electron acceptor other than oxygen
Answer: E
54 Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to A) perform amoeboid movement. B) form cleavage furrows. C) contract muscle fibers. D) extend pseudopodia. E) move vesicles around the cell.
Answer: E
54 card image Which drawing in the figure above depicts the electron configuration of an element with chemical properties most similar to Helium (₂He)? A) A B) B C) C D) D E) E
Answer: E
55 A major group of G protein-coupled receptors contains seven transmembrane α helices. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior face or on the cytosol face of the membrane. The loop on the cytosol side between helices 5 and 6 is usually substantially longer than the others. The coupled G protein most likely interacts with this receptor A) at the NH₃ end. B) at the COO- end. C) along the exterior margin. D) along the interior margin. E) at the loop between H5 and H6.
Answer: E
56 56) Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber? 1. Tropomyosin shifts and unblocks the cross-bridge binding sites. 2. Calcium is released and binds to the troponin complex. 3. Transverse tubules depolarize the sarcoplasmic reticulum. 4. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP. 5. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane. A) 1 → 2 → 3 → 4 → 5 B) 2 → 1 → 3 → 5 → 4 C) 2 → 3 → 4 → 1 → 5 D) 5 → 3 → 1 → 2 → 4 E) 5 → 3 → 2 → 1 → 4
Answer: E
57 card image 57) Study the information above about quail habitats. Assuming that only one quail can occupy a habitat where all cover requirements are met, what is the maximum number of quail that could inhabit any of the hypothetical plots shown? A) 1 B) 2 C) 4 D) 6 E) 9
Answer: E
57 card image 57) Which of the following graphs illustrates the growth curve of a small population of rodents that has grown to reach a static carrying capacity?
Answer: E
57 card image Which drawing in the figure above is of the electron configuration of a sodium ₁₁Na⁺ ion? A) A B) B C) C D) D E) E
Answer: E
58 What do the cell walls of plants and the extracellular matrix of animal cells have in common? A) They are largely composed of phospholipids and glycoproteins. B) Their proteins are made by free cytoplasmic ribosomes. C) They form rigid structures that provide structural support for cells but limit their expansion. D) They limit the passage of small molecules. E) They have functional connections with the cytoskeleton inside the cell.
Answer: E
6 6) At which phase are centrioles beginning to move apart in animal cells? A) telophase B) anaphase C) prometaphase D) metaphase E) prophase
Answer: E
6 6) Which of the following is an example of cryptic coloration? A) bands on a coral snake B) brown or gray color of tree bark C) markings of a viceroy butterfly's wings D) colors of an insect-pollinated flower's petals E) a "walking stick" insect that resembles a twig
Answer: E
60 60) Calcium ions regulate contraction of smooth muscle cells by binding to A) troponin. B) tropomyosin. C) actin. D) myosin. E) calmodulin.
Answer: E
60 The next question presumes that you have at least once visited and have some knowledge of the fast-food restaurant McDonald's. Use your knowledge of McDonald's and your understanding of community ecology to answer the following questions about an ecological community, McDonaldland. 60) Which two "species" are likely to compete for the same ecological niche? A) Big Mac and Quarter Pounder B) French Fries and Hash Browns C) Premium Caesar Salad with Crispy Chicken and Premium Crispy Chicken Classic Sandwich D) Filet-O-Fish and Double Cheeseburger E) No two species can ever occupy the same ecological niche.
Answer: E
60 There is a group of invertebrate animals called rotifers, among which a particular group of species reproduces, as far as is known, only asexually. These rotifers, however, have survived a long evolutionary history without evidence of having been overcome by excessive mutations. 60) Since the rotifers develop from eggs, but asexually, what can you predict? A) The eggs and the zygotes are all haploid. B) The animals are all hermaphrodites. C) While asexual, both males and females are found in nature. D) All males can produce eggs. E) No males can be found.
Answer: E
61 61) Your friend is wary of environmentalists' claims that global warming could lead to major biological change on Earth. Which of the following statements can you use in response to your friend's suspicions? A) We know that atmospheric carbon dioxide has increased over the past 150 years. B) Through measurements and observations, we know that CO2 levels and temperature fluctuations are directly correlated, even in prehistoric times. C) Global warming could have significant effects on agriculture in the United States. D) Sea levels will likely rise, displacing as much as 50% of the world's human population. E) All statements listed could be used.
Answer: E
61 There is a group of invertebrate animals called rotifers, among which a particular group of species reproduces, as far as is known, only asexually. These rotifers, however, have survived a long evolutionary history without evidence of having been overcome by excessive mutations. 61) Assuming that the eggs are diploid, tetraploid, or partially tetraploid, what mechanism may still occur without fertilization? A) meiosis in each generation B) meiosis in every second generation C) independent assortment of maternal and paternal chromosomes D) meiosis in times of adverse environmental conditions E) crossing over of homologs
Answer: E
62 card image Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species) 62) Examine this food web for a particular terrestrial ecosystem. Which species is most likely a decomposer on this food web? A) A B) B C) C D) D E) E
Answer: E
63 An organism is discovered that thrives both in the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism A) must use a molecule other than oxygen to accept electrons from the electron transport chain. B) is a normal eukaryotic organism. C) is photosynthetic. D) is an anaerobic organism. E) is a facultative anaerobe.
Answer: E
63 The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA A) is a six-carbon sugar and the sugar in RNA is a five-carbon sugar. B) can form a double-stranded molecule. C) is an aldehyde sugar and the sugar in RNA is a keto sugar. D) is in the α configuration and the sugar in RNA is in the β configuration. E) contains one less oxygen atom.
Answer: E
64 64) What is the single greatest threat to biodiversity? A) overharvesting of commercially important species B) introduced species that compete with native species C) pollution of Earth's air, water, and soil D) disruption of trophic relationships as more and more prey species become extinct E) habitat alteration, fragmentation, and destruction
Answer: E
64 Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through A) plasmodesmata. B) intermediate filaments. C) tight junctions. D) desmosomes. E) gap junctions.
Answer: E
64 Several organisms, primarily protists, have what are called intermediate mitotic organization. A) They represent a form of cell reproduction which must have evolved completely separately from those of other organisms. B) They demonstrate that these species are not closely related to any of the other protists and may well be a different kingdom. C) They rely on totally different proteins for the processes they undergo. D) They may be more closely related to plant forms that also have unusual mitosis. E) They show some but not all of the evolutionary steps toward complete mitosis.
Answer: E
64 card image Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species) 64) Examine this food web for a particular terrestrial ecosystem. Which pair of species could be omnivores? A) A and B B) A and D C) B and C D) C and D E) C and E
Answer: E
66 66) Among these choices, the most energetically efficient locomotion per unit mass is likely A) running by a 50-gram rodent. B) running by a 40-kg ungulate. C) flying by a 100-g bird. D) swimming by a 10-g minnow (bony fish). E) swimming by a 100-kg tuna (bony fish).
Answer: E
66 We can be sure that a mole of table sugar and a mole of vitamin C are equal in their A) mass in daltons. B) mass in grams. C) volume. D) number of atoms. E) number of molecules.
Answer: E
66 card image Refer to Figure 53.4 and then answer the following questions. Figure 53.4: Infant mortality and life expectancy at birth in developed and developing countries (data as of 2005). 66) In terms of demographics, which country is likely to experience the greatest population growth problem over the next ten years? A) Mexico, because there are fewer pre-reproductive individuals in their population B) China, whose population is more than a billion, but whose expected fertility rate is 1.8 children C) Germany, where the growth rate of the population is 0.1% per year D) United States (2009 population ~ 205,000,000, where 200,000 Americans are added to the population each day) E) Afghanistan, with a 3.85 annual growth rate
Answer: E
67 67) Which of the following biomes is correctly paired with the description of its climate? A) savanna-low temperature, precipitation uniform during the year B) tundra-long summers, mild winters C) temperate broadleaf forest-relatively short growing season, mild winters D) temperate grasslands-relatively warm winters, most rainfall in summer E) tropical forests-nearly constant day length and temperature
Answer: E
67 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the activation energy needed for the noncatalyzed reverse reaction, C + D → A + B, in Figure 8.1? A) a B) b C) c D) d E) e
Answer: E
67 card image What results from the chemical reaction illustrated above? A) a cation with a net charge of +1 B) a cation with a net charge of -1 C) an anion with a net charge of +1 D) an anion with a net charge of -1 E) a cation with a net charge of +1 and an anion with a net charge of -1
Answer: E
68 ECM proteins are made by ribosomes in which part of a eukaryotic cell? A) mitochondria B) cytoplasm C) nuclear envelope D) Golgi apparatus E) rough ER
Answer: E
69 A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.) A) 50°C B) 5°C C) 1°C D) 100°C E) 10°C
Answer: E
69 If cells are grown in a medium containing radioactive ³²P-labeled phosphate, which of these molecules will be labeled? A) phospholipids B) nucleic acids C) proteins D) amylose E) both phospholipids and nucleic acids
Answer: E
7 7) What would be the effect on climate in the temperature latitudes if Earth were to slow its rate of rotation from a 24-hour period of rotation to a 48-hour period of rotation? A) Seasons would be longer and more distinct (colder winters and warmer summers). B) There would be a smaller range between daytime high and nighttime low temperatures. C) Large scale weather events such as tornadoes and hurricanes would no longer be a part of regional climates. D) Winter seasons in both the northern and southern hemispheres would have more abundant and frequent precipitation events. E) The climate would stay the same. The only change would be longer days and nights.
Answer: E
7 Hermann Kolbe's synthesis of an organic compound, acetic acid, from inorganic substances that had been prepared directly from pure elements was a significant milestone for what reason? A) It solved an industrial shortage of acetic acid. B) It proved that organic compounds could be synthesized from inorganic compounds. C) It disproved the concept of vitalism. D) It showed that life originated from simple inorganic chemicals. E) It proved that organic compounds could be synthesized from inorganic compounds and disproved the concept of vitalism.
Answer: E
70 70) The feeding relationships among the species in a community determine the community's A) secondary succession. B) ecological niche. C) species richness. D) species-area curve. E) trophic structure.
Answer: E
71 A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. 71) When the cell has just completed telophase, which of the following does he see? A) a clear area in the center of the cell B) chromosomes clustered at the poles C) individual chromatids separating D) formation of vesicles at the midline E) two small cells with chromatin
Answer: E
71 How will brief heating (to 95°C) affect macromolecular structures in aqueous solution? A) DNA duplexes will unwind and separate. B) Proteins will unfold (denature). C) Starch will hydrolyze into monomeric sugars. D) Proteins will hydrolyze into amino acids. E) DNA duplexes will unwind and separate, and proteins will unfold (denature).
Answer: E
71 Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements correctly describes phosphofructokinase activity? A) It is inhibited by AMP. B) It is activated by ATP. C) It is activated by citrate, an intermediate of the citric acid cycle. D) It catalyzes the conversion of fructose 1,6-bisphosphate to fructose 6-phosphate, an early step of glycolysis. E) It is an allosteric enzyme.
Answer: E
71 biologist wants specifically to examine the surfaces of different types of cells in kidney tubules of small mammals. The cells in question can be distinguished by external shape, size, and 3-D characteristics. Which of the following would be the optimum method for her study? A) transmission electron microscopy B) cell fractionation C) light microscopy using stains specific to kidney function D) light microscopy of living unstained material E) scanning electron microscopy
Answer: E
74 74) A recent study of ecological footprints concluded that A) Earth's carrying capacity for humans is about 10 billion. B) Earth's carrying capacity would increase if per capita meat consumption increased. C) current demand by industrialized countries for resources is much smaller than the ecological footprint of those countries. D) it is not possible for technological improvements to increase Earth's carrying capacity for humans. E) the ecological footprint of the United States is large because per capita resource use is high.
Answer: E
74 In vertebrate animals, brown fat tissue's color is due to abundant blood vessels and capillaries. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few blood vessels or capillaries. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue? A) to increase the rate of oxidative phosphorylation from its few mitochondria B) to allow the animals to regulate their metabolic rate when it is especially hot C) to increase the production of ATP D) to allow other membranes of the cell to perform mitochondrial functions E) to regulate temperature by converting most of the energy from NADH oxidation to heat
Answer: E
74 card image Which of the following descriptors is true of the molecule shown in Figure 5.1? A) hexose B) fructose C) glucose D) hexose and fructose only E) hexose and glucose only
Answer: E
75 What is the purpose of beta oxidation in respiration? A) oxidation of glucose B) oxidation of pyruvate C) feedback regulation D) control of ATP accumulation E) breakdown of fatty acids
Answer: E
76 76) Experiments with genetically altered mice showed that the mice would consume abnormally high amounts of bitter-tasting compounds in water after their A) hormone receptors for digestive hormones were reduced or eliminated, showing that bitter tastes are reinforced by digestive responses. B) salt-taste cells were altered to express receptors for bitter tastants, suggesting that animals have unregulated salt appetites. C) visual sense was reduced or eliminated, suggesting that mice learn visual cues about bitter tastes. D) olfactory sense was reduced or eliminated, suggesting that mice learn odor cues about bitter tastes. E) sweet-taste cells were altered to express receptors for bitter tastants, suggesting that the sensation of taste depends only on which taste cell is stimulated.
Answer: E
77 77) Which of the following sensory receptors is incorrectly paired with its category? A) hair cellmechanoreceptor B) muscle spindlemechanoreceptor C) taste receptor-chemoreceptor D) rodelectromagnetic receptor E) olfactory receptorelectromagnetic receptor
Answer: E
77 Compared with ³¹P, the radioactive isotope ³²P has A) a different atomic number. B) a different charge. C) one more proton. D) one more electron. E) one more neutron.
Answer: E
77 card image The molecule shown in Figure 5.3 is a A) polysaccharide. B) polypeptide. C) saturated fatty acid. D) triacylglycerol. E) unsaturated fatty acid.
Answer: E
79 79) The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? A) spindle formation B) spindle attachment to kinetochores C) DNA synthesis D) cell elongation during anaphase E) cleavage furrow formation and cytokinesis
Answer: E
8 8) Which of the following examples would most accurately measure the density of the population being studied? A) counting the number of prairie dog burrows per hectare B) counting the number of times a 1 kilometer transect is intersected by tracks of red squirrels after a snowfall C) counting the number of coyote droppings per hectare D) multiplying the number of moss plants counted in 10 quadrats of 1m² each by 100 to determine the density per kilometer². E) counting the number of zebras from airplane census observations.
Answer: E
81 81) If you applied a fungicide to a cornfield, what would you expect to happen to the rate of decomposition and net ecosystem production (NEP)? A) Both decomposition rate and NEP would decrease. B) Both decomposition rate and NEP would increase. C) Neither would change. D) Decomposition rate would increase and NEP would decrease. E) Decomposition rate would decrease and NEP would increase.
Answer: E
86 [SEE IMAGE FOR CARD #84] Which of the following molecules contain(s) an aldehyde type of carbonyl functional group? A) 1 B) 4 C) 8 D) 10 E) 1 and 4
Answer: E
88 [SEE IMAGE FOR CARD #84] Which molecule is a saturated fatty acid? A) 1 B) 5 C) 6 D) 8 E) 9
Answer: E
89 [SEE IMAGE FOR CARD #84] Which of the following molecules is a purine type of nitrogenous base? A) 2 B) 3 C) 5 D) 12 E) 13
Answer: E
9 ) The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen? A) The nitrogen atom has a mass number of approximately 7 daltons and an atomic mass of 14. B) The nitrogen atom has a mass number of approximately 14 daltons and an atomic mass of 7. C) The nitrogen atom has a mass number of 14 and an atomic mass of 7 grams. D) The nitrogen atom has a mass number of 7 and an atomic number of 14. E) The nitrogen atom has a mass number of 14 and an atomic mass of approximately 14 daltons.
Answer: E
9 9) Which of the following assumptions have to be made regarding the capture-recapture estimate of population size? I. Marked and unmarked individuals have the same probability of being trapped. II. The marked individuals have thoroughly mixed with the population after being marked. III. No individuals have entered or left the population by immigration or emigration, and no individuals have been added by birth or eliminated by death during the course of the estimate. A) I only B) II only C) I and II only D) II and III only E) I, II, and III
Answer: E
9 Halobacterium has a photosynthetic membrane that is colored purple. Its photosynthetic action spectrum is exactly complementary (opposite to) the action spectrum for green plants. What wavelengths of light do the Halobacterium photosynthetic pigments absorb? A) red and yellow B) blue, green, and red C) green and yellow D) red and green E) blue and red
Answer: E
9 When Stanley Miller applied heat and electrical sparks to a mixture of simple inorganic compounds such as methane, hydrogen gas, ammonia, and water vapor, what compounds were produced? A) mostly amino acids B) only simple organic compounds such as formaldehyde and cyanide C) mostly hydrocarbons D) only simple inorganic compounds E) both simple organic compounds and more complex organic compounds such as amino acids and hydrocarbons
Answer: E
9 Where does glycolysis take place in eukaryotic cells? A) mitochondrial matrix B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial inter membrane space E) cytosol
Answer: E
91 card image For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle (see Figure 9.2), what is the total number of NADH + FADH₂ molecules produced? A) 4 B) 5 C) 6 D) 10 E) 12
Answer: E
96 [SEE IMAGE FOR CARD #84] Which of the following molecules contains a glycosidic linkage type of covalent bond? A) 4 B) 6 C) 12 D) 13 E) 15
Answer: E
99 [SEE IMAGE FOR CARD #84] Which of the following statements is false? A) Molecules 1 and 4 could be joined together by a glycosidic linkage to form a disaccharide. B) Molecules 9 and 10 could be joined together by ester bonds to form a triacylglycerol. C) Molecules 2 and 7 could be joined together to form a short peptide. D) Molecules 2, 7, and 8 could be joined together to form a short peptide. E) Molecules 14 and 15 could be joined together to form a polypeptide.
Answer: E
Topic: Concept 50.5 59 59) Skeletal, cardiac, and smooth muscle all have A) A bands and I bands. B) transverse tubules. C) gap junctions. D) motor units. E) thick and thin filaments.
Answer: E
molecular mass = 92) would be present in 1 L of a 1 M glycerol solution? A) 1 × 10⁶ B) 14 × 6.02 × 10²³ C) 92 × 6.02 × 10²³ D) 6.02 × 10²⁶ E) 6.02 × 10²³
Answer: E
muscle contraction
Answer: E
solution Y has a pH of 7. From this information, we can reasonably conclude that A) solution Y has no free hydrogen ions (H⁺). B) the concentration of hydrogen ions in solution X is 30 times as great as the concentration of hydrogen ions in solution Y. C) the concentration of hydrogen ions in solution Y is 1,000 times as great as the concentration of hydrogen ions in solution X. D) the concentration of hydrogen ions in solution X is 3 times as great as the concentration of hydrogen ions in solution Y. E) the concentration of hydrogen ions in solution X is 1,000 times as great as the concentration of hydrogen ions in solution Y.
Answer: E
the reaction will stay at equilibrium.
Answer: E
the secondary and tertiary structures may or may not be altered.
Answer: E
therefore, this curve could not happen in nature.
Answer: E
46 46) All cell cycle checkpoints are similar in which way? A) They respond to the same cyclins. B) They utilize the same Cdks. C) They give the go-ahead signal to progress to the next checkpoint. D) They each have only one cyclin
Cdk complex. E) They activate or inactivate other proteins./ Answer: E
41 When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the A) formation of ATP. B) reduction of NAD⁺. C) restoration of the Na⁺
K⁺ balance across the membrane. D) creation of a proton-motive force. E) lowering of pH in the mitochondrial matrix./ Answer: D
40 40) Which of the following is a correct statement about the McArthur
Wilson Island Equilibrium Model? A) The more species that inhabit an island, the lower the extinction rate. B) As the number of species on an island increases, the emigration rate decreases. C) Competitive exclusion is less likely on an island that has large numbers of species. D) Small islands receive few new immigrant species. E) Islands closer to the mainland have higher extinction rates./ Answer: D
51 The following is a list of biology themes discussed in Chapter 1. Use them to answer questions 51 - 54. I. New properties emerge at each level in the biological hierarchy. II. Organisms interact with other organisms and the physical environment. III. Life requires energy transfer and transformation. IV. Structure and function are correlated at all levels of biological organization. V. Cells are an organism's basic units of structure and function. VI. The continuity of life is based on heritable information in the form of DNA. VII. Feedback mechanisms regulate biological systems. VIII. Evolution accounts for the unity and diversity of life. Which theme(s) is
are best illustrated by an experiment in which a biologist seeks a medication that will inhibit pain responses in a cancer patient? A) II B) VII C) III and V D) V and VIII E) VI and VII/ Answer: B
36 36) To view and analyze human chromosomes in a dividing cell, which of the following is
are required? A) electron microscope B) radioactive staining C) fluorescent staining D) DNA stain and a light microscope E) a stain particular to human cells/ Answer: D
79 card image Which of the following statements is
are true regarding the chemical reaction illustrated in Figure 5.5? A) It is a hydrolysis reaction. B) It results in a peptide bond. C) It joins two fatty acids together. D) It is a hydrolysis reaction and it results in a peptide bond. E) It is a hydrolysis reaction, it results in a peptide bond, and it joins two fatty acids together./ Answer: B
28 Similarities and differences among
between life-forms over time are most efficiently recorded by scientists in which field(s) of study? A) paleontology B) paleontology and anatomy C) paleontology, anatomy, and taxonomy D) paleontology, anatomy, taxonomy, and genetics E) paleontology, anatomy, taxonomy, genetics, and ecology/ Answer: E
25 The organic molecules in living organisms have a measurably lower ratio of carbon-13
carbon-12, two stable isotopes of carbon that comprise approximately 1.1% and 98.9% of atmospheric carbon, respectively. What is a reasonable explanation for this phenomenon? A) Photosynthesis preferentially uses carbon dioxide molecules with carbon-12, and the lower carbon-13/carbon-12 ratio propagates through the food chain. B) Carbon dioxide molecules with carbon-13 stay in the upper atmosphere and are less available to terrestrial plants and algae. C) Carbon-13 has a different valence electron configuration and is therefore less chemically reactive than carbon-12. D) Oxygen atoms preferentially react with carbon-13, thereby enriching the atmosphere with carbon dioxide molecules containing carbon-13 atoms. E) Carbon dioxide molecules containing carbon-13 are heavier and sink into the ocean depths, making them less available to living organisms./ Answer: A
25 25) Which of the following investigations would shed the most light on the distribution of organisms in temperate regions that are faced with climate change? A) Remove, to the mineral soil, all of the organisms from an experimental plot and monitor the colonization of the area over time in terms of both species diversity and abundance. B) Look back at the changes that occurred since the Ice Age and how species redistributed as glaciers melted, then make predictions on future distribution in species based on past trends. C) Compare and contrast the flora and fauna of warm
cold/dry/wet climates to shed light on how they evolved to be suited to their present-day environment. D) Quantify the impact of man's activities on present-day populations of threatened and endangered species to assess the rate of extirpation and extinction. E) There is no scientific investigation that can help make predictions on the future distribution of organisms./ Answer: B
19 card image 19) Exponential growth of a population is represented by dN
dt = A. SEE IMAGE B. SEE IMAGE C. SEE IMAGE D. SEE IMAGE E. SEE IMAGE/ Answer: B
25 card image 25) Logistic growth of a population is represented by dN
dt = A. SEE IMAGE B. SEE IMAGE C. SEE IMAGE D. SEE IMAGE E. SEE IMAGE/ Answer: D
21 21) Which of the following is the equation for zero population growth (ZPG)? A) R = b - m B) dN
dt = rN C) dN/dt =rmax N (K -N)/K D) dN/dt =rmax N E) dN/dt = 1.0N/ Answer: A
32 32) Which of the following species was driven to extinction by overexploitation by hunters
fishermen? A) African elephant B) the great auk C) North American bluefin tuna D) flying foxes E) American bison/ Answer: B
62 The next question presumes that you have at least once visited and have some knowledge of the fast-food restaurant McDonald's. Use your knowledge of McDonald's and your understanding of community ecology to answer the following questions about an ecological community, McDonaldland. 62) In a two-week marketing analysis, McDonald's was interested in finding out the popularity of the Big Mac. Using the realized
fundamental niche concept of community ecology, what should the marketing researchers do? A) Study the sales of McDonald's restaurants that are in close proximity to other fast-food restaurants. B) Serve only Big Macs at McDonald's and analyze the sales. C) Remove the Quarter Pounder from the menu and see if Big Mac sales increase. D) Serve Big Macs without the special sauce to see if sales go down. E) Serve Big Macs during breakfast hours./ Answer: C
28 28) Which of the following ecosystems would likely have a larger net primary productivity
hectare and why? A) open ocean because of the total biomass of photosynthetic autotrophs B) grassland because of the small standing crop biomass that results from consumption by herbivores and rapid decomposition C) tropical rain forest because of the massive standing crop biomass and species diversity D) cave due to the lack of photosynthetic autotrophs E) tundra because of the incredibly rapid period of growth during the summer season/ Answer: B
53 53) How do altruistic behaviors arise through natural selection? A) By his
her actions, the altruist increases the likelihood that some of its genes will be passed on to the next generation. B) The altruist is appreciated by other members of the population because their survivability has been enhanced by virtue of his/her risky behavior. C) Animals that perform altruistic acts are allowed by their population to breed more, thereby passing on their behavior genes to future generations. D) Altruistic behaviors lower stress in populations, which increases the survivability of all the members of the population. E) All of the options are correct./ Answer: A
46 46) An ecological footprint is a construct that is useful A) for a person living in a developed nation to consider to make better choices when using global food and energy resources. B) for a person living in a developing country to see how much of the world's resources are left for him
her. C) in converting human foods' meat biomass to plant biomass. D) in making predictions about the global carrying capacity of humans. E) in determining which nations produce the least amount of carbon dioxide from the burning of fossil fuels./ Answer: A
48 48) During the course of the formation of a parasite
host relationship, a critical first step in this evolution would be A) changing the behavior of the host or intermediate host. B) developing asexual reproduction. C) deriving nourishment without killing the host. D) starting as an ectoparasite and then later becoming an endoparasite. E) utilizing heterotropic nutrition during infection and autotrophic nutrition during dormancy./ Answer: C
26 26) Which series is correctly layered from top to bottom in a tropical rain forest? A) ground layer, shrub
immature layer, under story, canopy, emergent layer B) canopy, emergent layer, under story, shrub/immature layer, ground layer C) canopy, under story, shrub/immature layer, emergent layer, ground layer D) emergent layer, canopy, under story, shrub/immature layer, ground layer E) emergent layer, under story, canopy, ground layer, shrub/immature layer/ Answer: D
18 The free energy for the oxidation of glucose to CO₂ and water is -686 kcal
mol and the free energy for the reduction of NAD⁺ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed? A) Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis. B) Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat. C) Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. D) There is no CO₂ or water produced as products of glycolysis. E) Glycolysis consists of many enzymatic reactions, each of which extracts some energy from the glucose molecule. Answer: C 19 Starting with one molecule of glucose, the energy-containing products of glycolysis are A) 2 NAD⁺, 2 pyruvate, and 2 ATP. B) 2 NADH, 2 pyruvate, and 2 ATP. C) 2 FADH₂, 2 pyruvate, and 4 ATP. D) 6 CO₂, 2 ATP, and 2 pyruvate. E) 6 CO₂, 30 ATP, and 2 pyruvate./ Answer: B
22 For the hydrolysis of ATP to ADP + Pi, the free energy change is -7.3 kcal
mol under standard conditions (1 M concentration of both reactants and products). In the cellular environment, however, the free energy change is about -13 kcal/mol. What can we conclude about the free energy change for the formation of ATP from ADP and Pi under cellular conditions? A) It is +7.3 kcal/mol. B) It is less than +7.3 kcal/mol. C) It is about +13 kcal/mol. D) It is greater than +13 kcal/mol. E) The information given is insufficient to deduce the free energy change./ Answer: C
35 During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal
mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction? A) -40 kcal/mol B) -20 kcal/mol C) 0 kcal/mol D) +20 kcal/mol E) +40 kcal/mol/ Answer: B
21 The molar mass of glucose (C₆H₁₂O₆) is 180 g
mol. Which of the following procedures should you carry out to make a 0.5 M solution of glucose? A) Dissolve 0.5 g of glucose in a small volume of water, and then add more water until the total volume of solution is 1 L. B) Dissolve 90 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L. C) Dissolve 180 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L. D) Dissolve 0.5 g of glucose in 1 L of water. E) Dissolve 180 g of glucose in 0.5 L of water./ Answer: B
20 The molar mass of glucose is 180 g
mol. Which of the following procedures should you carry out to make a 1 M solution of glucose? A) Dissolve 1 g of glucose in 1 L of water. B) Dissolve 180 g of glucose in 1 L of water. C) Dissolve 180 g of glucose in 180 g of water. D) Dissolve 180 milligrams (mg) of glucose in 1 L of water. E) Dissolve 180 g of glucose in 0.8 L of water, and then add more water until the total volume of the solution is 1 L./ Answer: E
68 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Assume that the reaction in Figure 8.1 has a ΔG of -5.6 kcal
mol. Which of the following would be true? A) The reaction could be coupled to power an endergonic reaction with a ΔG of +6.2 kcal/mol. B) The reaction could be coupled to power an exergonic reaction with a ΔG of +8.8 kcal/mol. C) The reaction would result in a decrease in entropy (S) and an increase in the total energy content (H) of the system. D) The reaction would result in an increase in entropy (S) and a decrease in the total energy content (H) of the system. E) The reaction would result in products (C + D) with a greater free-energy content than in the initial reactants (A + B)./ Answer: D
17 17) Introduced species can have deleterious effects on biological communities by A) preying on native species. B) competing with native species for food or light. C) displacing native species. D) competing with native species for space or breeding
nesting habitat. E) All of the options are correct./ Answer: E
43 43) A population of white-footed mice becomes severely overpopulated in a habitat that has been disturbed by human activity. Sometimes intrinsic factors cause the population to increase in mortality and lower reproduction rates to occur in reaction to the stress of overpopulation. Which of the following is an example of intrinsic population control? A) Owl populations frequent the area more often because of increased hunting success. B) Females undergo hormonal changes that delay sexual maturation and many individuals suffer depressed immune systems and die due to the stress of overpopulation. C) Clumped dispersion of the population leads to increased spread of disease and parasites, resulting in a population crash. D) All of the resources (food and shelter) are used up by overpopulation and much of the population dies of exposure and
or starvation. E) Because the individuals are vulnerable they are more likely to die off if a drought or flood were to occur./ Answer: B
4 4) The law of conservation of matter states that matter cannot be created, yet matter is sometimes gained or lost to an ecosystem. What is the reason for this seeming contradiction? A) Chemoautotrophic organisms can convert matter to energy. B) Matter can be moved in
out of an ecosystem from/to another ecosystem. C) Photosynthetic organisms convert solar energy to sugars. D) Detrivores convert matter to energy. E) Heterotrophs convert heat to energy./ Answer: B
22 22) The introduction of the brown tree snake in the 1940s to the island of Guam has resulted in A) eradication of non-native rats and other undesirable
pest species. B) the extirpation of many of the island's bird and reptile species. C) a good lesson in biological control. D) a new species of hybrids from crossbreeding with a native snake species. E) its failure to compete with native species and its quick elimination from the island./ Answer: B
16 Since steroid receptors are located intracellularly, which of the following is true? A) The receptor molecules are themselves lipids or glycolipids. B) The steroid
receptor complex can cross the nuclear membrane. C) The unbound steroid receptors are quickly recycled by lysosomes. D) The concentration of steroid receptors must be relatively high in most cells. E) The receptor molecules are free to move in and out of most organelles./ Answer: B
38 In which of the following ways could signal transduction most probably be explored in research to treat cancer? A) removal of serine
threonine phosphate acceptors from transduction pathways in colon pre-cancerous growths B) alteration of protein kinases in cell cycle regulation in order to slow cancer growth C) increase in calcium ion uptake into the cytoplasm in order to modulate the effects of environmental carcinogens D) expansion of the role of transduction inhibitors in the cells before they give rise to cancer E) increase in the concentration of phosphodiesterases in order to produce more AMP/ Answer: B
23 23) Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist than gross primary production (GPP)? A) NPP can be expressed in energy
unit of area/unit of time. B) NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem. C) NPP represents the stored chemical energy that is available to consumers in the ecosystem. D) NPP is the same as the standing crop. E) NPP shows the rate at which the standing crop is utilized by consumers./ Answer: C
15 15) A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? A) 63 chromosomes in 31 1
2 pairs B) 63 chromosomes in 21 sets of 3 C) 63 chromosomes, each with three chromatids D) 21 chromosome pairs and 21 unique chromosomes/ Answer: B
56 card image For the enzyme-catalyzed reaction shown in the figure, which of these treatments will cause the greatest increase in the rate of the reaction, if the initial reactant concentration is 1.0 micromolar? A) doubling the activation energy needed B) cooling the reaction by 10°C C) doubling the concentration of the reactants to 2.0 micromolar D) doubling the enzyme concentration E) increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1
2/ Answer: D
21 The atomic number of each atom is given to the left of each of the elements below. Which of the atoms has the same valence as carbon (12
6 C)? A) ₇N nitrogen B) ₉F flourine C) ₁₀Ne neon D) ₁₂Mg magnesium E) ₁₄Si silicon/ Answer: E
25 The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that A) at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope. B) the nuclear envelope is not part of the endomembrane system. C) the nuclear envelope is physically separated from the endoplasmic reticulum. D) small vesicles from the Golgi fuse with the nuclear envelope. E) nuclear pore complexes contain proteins.
Answer: A
37 The reactions that produce molecular oxygen (O₂) take place in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but are not part of photosynthesis.
Answer: A
46 46) Which of the following locations is the reservoir for nitrogen in the nitrogen cycle? A) atmosphere B) sedimentary bedrock C) fossilized plant and animal remains (coal, oil, and natural gas) D) plant and animal biomass E) soil
Answer: A
46 Which of the following is not considered to be a weak molecular interaction? A) a covalent bond B) a van der Waals interaction C) an ionic bond in the presence of water D) a hydrogen bond E) both a hydrogen bond and a covalent bond
Answer: A
5 5) Artificial electrical stimulation of a human's menthol-sensitive neurons would likely produce the sensation of A) cold temperature. B) hot temperature. C) tactile stimulus. D) odor of pepper. E) deep pressure.
Answer: A
56 card image Which component is the fiber of the extracellular matrix? A) A B) B C) C D) D E) E
Answer: A
59 card image Which temperature and pH profile curves on the graphs were most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid? A) curves 1 and 4 B) curves 1 and 5 C) curves 2 and 4 D) curves 2 and 5 E) curves 3 and 4
Answer: A
64 card image Which line in the graph represents the bag with the highest initial concentration of sucrose? A) A B) B C) C D) D E) E
Answer: A
70 card image Which of the trees in this figure groups the domains according to similarities in cellular size and architecture? A) A B) B C) C D) D
Answer: A
8 8) If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter cell following cytokinesis? A) 10 B) 20 C) 30 D) 40 E) 80
Answer: A
15 How many structural isomers are possible for a substance having the molecular formula C₄H₁₀? A) 1 B) 2 C) 4 D) 3 E) 11
Answer: B
26 26) Aquatic ecosystems are least likely to be limited by which of the following nutrients? A) nitrogen B) carbon C) phosphorus D) iron E) zinc
Answer: B
33 Which organelle often takes up much of the volume of a plant cell? A) lysosome B) vacuole C) mitochondrion D) Golgi apparatus E) peroxisome
Answer: B
40 The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride? A) MgCl B) MgCl₂ C) Mg₂Cl D) Mg₂Cl₂ E) MgCl₃
Answer: B
45 45) Myasthenia gravis is a form of muscle paralysis in which A) motor neurons lose their myelination and the ability to rapidly fire action potentials. B) acetylcholine receptors are destroyed by an overactive immune system. C) ATP production becomes uncoupled from mitochondrial electron transport. D) the spinal cord is infected with a virus that attacks muscle stretch receptors. E) troponin molecules become unable to bind calcium ions.
Answer: B
61 card image In the figure above, how many electrons does nitrogen have in its valence shell? A) 2 B) 5 C) 7 D) 8 E) 14
Answer: B
61 card image Which molecule shown above is a thiol? A) A B) B C) C D) D E) E
Answer: B
81 card image Which step in Figure 9.1 shows a split of one molecule into two smaller molecules? A) A B) B C) C D) D E) E
Answer: B
alignment determines independent assortment. A) I B) II C) IV D) VI E) VIII
Answer: B
12 Which of the following is true of integral membrane proteins? A) They lack tertiary structure. B) They are loosely bound to the surface of the bilayer. C) They are usually transmembrane proteins. D) They are not mobile within the bilayer. E) They serve only a structural role in membranes.
Answer: C
17 Which of these are not embedded in the hydrophobic portion of the lipid bilayer at all? A) transmembrane proteins B) integral proteins C) peripheral proteins D) integrins E) glycoproteins
Answer: C
2 Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants? A) nitrogen B) calcium C) iodine D) sodium E) phosphorus
Answer: C
24 Amino acids are acids because they always possess which functional group? A) amino B) carbonyl C) carboxyl D) phosphate E) hydroxyl
Answer: C
27 27) A salmon returns to its home stream to spawn. What term best applies to this behavior? A) sign stimulus B) cognition C) imprinting D) classical conditioning E) operant conditioning
Answer: C
27 27) Umami perception follows the oral presence of A) sugar water. B) a rich chocolate flavor. C) a savory and complex cheese. D) acidic orange juice. E) salt water.
Answer: C
30 card image The two molecules shown in the figure above are best described as A) optical isomers. B) enantiomers. C) structural isomers. D) cis-trans isomers. E) chain length isomers.
Answer: C
34 Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein? A) 101 B) 100 C) 99 D) 98 E) 97
Answer: C
36 36) Owls eat rats, mice, shrews, and small birds. Assume that, over a period of time, an owl consumes 5,000 J of animal material. The owl loses 2,300 J in feces and owl pellets and uses 2,500 J for cellular respiration. What is the primary efficiency of this owl? A) 0.02% B) 1% C) 4% D) 10% E) 40%
Answer: C
40 The sodium-potassium pump is called an electrogenic pump because it A) pumps equal quantities of Na⁺ and K⁺ across the membrane. B) pumps hydrogen ions out of the cell. C) contributes to the membrane potential. D) ionizes sodium and potassium atoms. E) is used to drive the transport of other molecules against a concentration gradient.
Answer: C
48 48) In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are A) Rhizobium bacteria. B) nitrifying bacteria. C) denitrifying bacteria. D) methanogenic protozoans. E) nitrogen-fixing bacteria.
Answer: C
52 If cells are grown in a medium containing radioactive ³⁵S, which of these molecules will be labeled? A) phospholipids B) nucleic acids C) proteins D) amylose E) both proteins and nucleic acids
Answer: C
57 If ¹⁴C-labeled uridine triphosphate is added to the growth medium of cells, what macromolecules will be labeled? A) phospholipids B) DNA C) RNA D) both DNA and RNA E) proteins
Answer: C
6 When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes A) hydrolyzed. B) hydrogenated. C) oxidized. D) reduced. E) an oxidizing agent.
Answer: C
60 Which of the following best demonstrates the unity among all organisms? A) matching DNA nucleotide sequences B) descent with modification C) the structure and function of DNA D) natural selection E) emergent properties
Answer: C
63 63) Chitin is a major component of A) the skeleton of mammals. B) the hydrostatic skeletons of earthworms. C) the exoskeleton of insects. D) the body hairs of mammals. E) the skeleton in birds.
Answer: C
66 When an individual is exercising heavily and when the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells? A) It is converted to NAD⁺. B) It produces CO₂ and water. C) It is taken to the liver and converted back to pyruvate. D) It reduces FADH₂ to FAD⁺. E) It is converted to alcohol.
Answer: C
66 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the activation energy required for a noncatalyzed reaction in Figure 8.1? A) a B) b C) c D) d E) e
Answer: C
78 card image What is the structure shown in Figure 5.4? A) pentose molecule B) fatty acid molecule C) steroid molecule D) oligosaccharide molecule E) phospholipid molecule
Answer: C
80 card image At which bond would water need to be added to achieve hydrolysis of the peptide, back to its component amino acid? A) A B) B C) C D) D E) E
Answer: C
81 card image Which bond is a peptide bond? A) A B) B C) C D) D E) E
Answer: C
and DNA nucleotides contain a different sugar than RNA nucleotides.
Answer: C
101 The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the A) oxidation of glucose and other organic compounds. B) flow of electrons down the electron transport chain. C) affinity of oxygen for electrons. D) H⁺ concentration across the membrane holding ATP synthase. E) transfer of phosphate to ADP.
Answer: D
17 Which organelle or structure is absent in plant cells? A) mitochondria B) Golgi vesicles C) microtubules D) centrosomes E) peroxisomes
Answer: D
29 If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound A) that mimics epinephrine and can bind to the epinephrine receptor. B) that stimulates cAMP production in liver cells. C) to stimulate G protein activity in liver cells. D) that increases phosphodiesterase activity. E) that does any of the above.
Answer: D
3 A primary objective of cell fractionation is to A) view the structure of cell membranes. B) sort cells based on their size and weight. C) determine the size of various organelles. D) separate the major organelles so that their particular functions can be determined. E) separate lipid-soluble from water-soluble molecules.
Answer: D
33 What is the hydrogen ion [H⁺] concentration of a solution of pH 8? A) 8 M B) 8 x 10⁻⁶ M C) 0.01 M D) 10⁻⁸ M E) 10⁻⁶ M
Answer: D
38 Mutations that result in single amino acid substitutions in an enzyme A) can have no effect on the activity or properties of the enzyme. B) will almost always destroy the activity of the enzyme. C) will often cause a change in the substrate specificity of the enzyme. D) may affect the physicochemical properties of the enzyme such as its optimal temperature and pH. E) may, in rare cases, cause the enzyme to run reactions in reverse.
Answer: D
38 Which of the following statements is true about buffer solutions? A) They maintain a constant pH when bases are added to them but not when acids are added to them. B) They maintain a constant pH when acids are added to them but not when bases are added to them. C) They maintain a relatively constant pH of approximately 7 when either acids or bases are added to them. D) They maintain a relatively constant pH when either acids or bases are added to them. E) They are found only in living systems and biological fluids.
Answer: D
39 A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. A) The dissolved oxygen in the flask with algae will always be higher. B) The dissolved oxygen in the flask with algae will always be lower. C) The dissolved oxygen in the flask with algae will be higher in the light, but the same in the dark. D) The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark. E) The dissolved oxygen in the flask with algae will not be different from the control flask at any time.
Answer: D
39 Energy released by the electron transport chain is used to pump H⁺ into which location in eukaryotic cells? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix
Answer: D
45 45) The evolution of mating systems is most likely affected by A) population density. B) territoriality. C) certainty of paternity. D) sexual dimorphism. E) None of the options is correct.
Answer: D
45 45) What is a critical load? A) the amount of nutrient augmentation necessary to bring a depleted habitat back to its former level B) the level of a given toxin in an ecosystem that is lethal to 50% of the species present C) the maximum abundance level of a particular species, beyond which additional numbers will degrade a habitat D) the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity E) the number of predators an ecosystem can support that effectively culls prey populations to healthy levels
Answer: D
46 46) In which community would organisms most likely have adaptations enabling them to respond to different photoperiods? A) tropical forest B) coral reef C) savanna D) temperate forest E) abyssal
Answer: D
50 card image Which of the groups above is a basic functional group that can accept H⁺ and become positively charged? A) A B) B C) C D) D E) E
Answer: D
54 card image 54) If the cell whose nuclear material is shown in Figure 12.2 continues toward completion of mitosis, which of the following events would occur next? A) cell membrane synthesis B) spindle fiber formation C) nuclear envelope breakdown D) formation of telophase nuclei E) synthesis of chromatids
Answer: D
54 card image Which component is the peripheral protein? A) A B) B C) C D) D E) E
Answer: D
58 card image Which drawing in the figure above depicts the most electronegative atom? A) A B) B C) C D) D E) E
Answer: D
59 The cell walls of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic common to all of these extracellular structures? A) They must block water and small molecules in order to regulate the exchange of matter and energy with their environment. B) They must permit information transfer between the cell's cytoplasm and the nucleus. C) They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume. D) They are constructed of polymers that are synthesized in the cytoplasm and then transported out of the cell. E) They are composed of a mixture of lipids and carbohydrates.
Answer: D
59 card image The diagram shows a generalized cross section of the marine environment with various zones labeled with letters. Choose the letter that best answers the question. Letters may be used once, more than once, or not at all 59) Which zone has the lowest biomass per unit of area? A) A B) B C) C D) D E) E
Answer: D
6 Whenever energy is transformed, there is always an increase in the A) free energy of the system. B) free energy of the universe. C) entropy of the system. D) entropy of the universe. E) enthalpy of the universe.
Answer: D
60 card image 60) Which of the following graphs illustrates the growth over several seasons of a population of snowshoe hares that were introduced to an appropriate habitat also inhabited by predators in northern Canada?
Answer: D
61 A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its A) nuclear lamina and nuclear matrix. B) nuclear matrix and extracellular matrix. C) mitochondria and Golgi apparatus. D) Golgi apparatus and extracellular matrix. E) nuclear pores and secretory vesicles.
Answer: D
61 card image This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the ΔG of the reaction in Figure 8.1? A) a B) b C) c D) d E) e
Answer: D
63 63) The main cause of the increase in the amount of CO₂ in Earth's atmosphere over the past 150 years is A) increased worldwide primary production. B) increased worldwide standing crop. C) an increase in the amount of infrared radiation absorbed by the atmosphere. D) the burning of larger amounts of wood and fossil fuels. E) additional respiration by the rapidly growing human population.
Answer: D
65 65) Which life cycle stage is found in plants but not animals? A) gamete B) zygote C) multicellular diploid D) multicellular haploid E) unicellular diploid
Answer: D
65 Which of the following makes it necessary for animal cells, although they have no cell walls, to have intercellular junctions? A) Cell membranes do not distinguish the types of ions and molecules passing through them. B) Large molecules, such as proteins and RNA molecules, do not readily get through one, much less two, adjacent cell membranes. C) Cell-to-cell communication requires physical attachment of one cell to another. D) Maintenance of tissue integrity and barriers to fluid leakage requires cells to adhere tightly to one another. E) The relative shapelessness of animal cells requires a mechanism for keeping the cells aligned.
Answer: D
68 68) Which of the following is characteristic of most terrestrial biomes? A) annual average rainfall in excess of 250 cm B) a distribution predicted almost entirely by rock and soil patterns C) clear boundaries between adjacent biomes D) vegetation demonstrating vertical layering E) cold winter months
Answer: D
68 Which of the following hydrocarbons has a double bond in its carbon skeleton? A) C₃H₈ B) C₂H₆ C) CH₄ D) C₂H₄ E) C₂H₂
Answer: D
68 Which of the following is an example of hydrolysis? A) the reaction of two monosaccharides, forming a disaccharide with the release of water B) the synthesis of two amino acids, forming a peptide with the release of water C) the reaction of a fat, forming glycerol and fatty acids with the release of water D) the reaction of a fat, forming glycerol and fatty acids with the consumption of water E) the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water
Answer: D
68 card image 68) On the diagram of the nitrogen cycle, which number represents ammonia (NH₄+)? A) 1 B) 2 C) 3 D) 4
Answer: D
68 card image What is the atomic number of the cation formed in the reaction illustrated above? A) 1 B) 8 C) 10 D) 11 E) 16
Answer: D
69 69) Imagine that you are managing a large game ranch. You know from historical accounts that a species of deer used to live there, but they have been extirpated. You decide to reintroduce them. After doing some research to determine what might be an appropriately sized founding population, you do so. You then watch the population increase for several generations, and graph the number of individuals (vertical axis) against the number of generations (horizontal axis). The graph will likely appear as A) a diagonal line, getting higher with each generation. B) an "S," increasing with each generation. C) an upside-down "U." D) a "J," increasing with each generation. E) an "S" that ends with a vertical line.
Answer: D
69 card image 69) The sense of head motion begins with sensory transduction by the structures at which numbers? A) 2, 3, and 4. B) 2, 5, and 7. C) 4. D) 5. E) 7 and 8.
Answer: D
69 card image Which of the following is the most correct interpretation of the figure? A) Inorganic phosphate is created from organic phosphate. B) Energy from catabolism can be used directly for performing cellular work. C) ADP + Pi are a set of molecules that store energy for catabolism. D) ATP is a molecule that acts as an intermediary to store energy for cellular work. E) Pi acts as a shuttle molecule to move energy from ATP to ADP.
Answer: D
11 11) In mountainous areas of western North America, north-facing slopes would be expected to A) receive more sunlight than similar southern exposures. B) be warmer and drier than comparable southern exposed slopes. C) consistently be steeper than southern exposures. D) support biological communities similar to those found at lower elevations on similar south-facing slopes. E) support biological communities similar to those found at higher elevations on similar south-facing slopes.
Answer: E
26 During cellular respiration, acetyl CoA accumulates in which location? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix
Answer: E
31 What is the pH of a 1 millimolar NaOH solution? A) pH 3 B) pH 8 C) pH 9 D) pH 10 E) pH 11
Answer: E
33 33) The cyclin component of MPF is destroyed toward the end of which phase? A) G₀ B) G₁ C) S D) G₂ E) M
Answer: E
42 card image In which of the structures illustrated above are the atoms bonded by ionic bonds? A) A B) B C) C D) C, D, and E only E) none of the structures
Answer: E
43 43) For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes? A) 23 B) 46 C) 460 D) 920 E) about 8 million
Answer: E
46 Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C₆H₁₂O₆) in aerobic cellular respiration? A) 2 B) 4 C) 15 D) 30-32 E) 60-64
Answer: E
5 5) Animal communication involves what type of sensory information? A) visual B) auditory C) olfactory D) tactile E) visual, auditory, olfactory, and tactile
Answer: E
70 If cells are grown in a medium containing radioactive ¹⁵N, which of these molecules will be labeled? A) fatty acids only B) nucleic acids only C) proteins only D) amylase only E) both proteins and nucleic acids
Answer: E
71 card image 71) The organ of Corti is represented by which number? A) 3. B) 4. C) 5. D) 6. E) 7.
Answer: E
79 79) The Hubbard Brook watershed deforestation experiment yielded all of the following results except: A) Most minerals were recycled within a forest ecosystem. B) The flow of minerals out of a natural watershed was offset by minerals flowing in. C) Deforestation increased water runoff. D) The nitrate concentration in waters draining the deforested area became dangerously high. E) Calcium levels remained high in the soil of deforested areas.
Answer: E
9 All of the following are part of a prokaryotic cell except A) DNA. B) a cell wall. C) a plasma membrane. D) ribosomes. E) an endoplasmic reticulum.
Answer: E
and they do not exhibit density-dependent inhibition when growing in culture.
Answer: E
40 40) A particular cyclin called cyclin E forms a complex with Cdk 2 (cyclin-dependent kinase 2). This complex is important for the progression of the cell from G₁ into the S phase of the cell cycle. Which of the following statements is correct? A) The amount of free cyclin E is greatest during the S phase. B) The amount of free Cdk 2 is greater during G₁ compared to the S phase. C) The amount of free cyclin E is highest during G₁. D) The amount of free Cdk 2 is greatest during G₁. E) The activity of the cyclin E
Cdk 2 complex is highest during G₂./ Answer: C
32 32) Sensory transduction of light
dark information in the vertebrate retina is accomplished by A) ganglion cells. B) amacrine cells. C) bipolar cells. D) horizontal cells. E) rods and cones./ Answer: E
39 39) Cowbirds utilize fragmented forests effectively by A) feeding on the fruits of shrubs that tend to grow at the forest
open-field interface. B) parasitizing the nests of forest birds, and feeding on open-field insects. C) roosting in forest trees, and nesting in grassy fields. D) outcompeting other songbird species in fragmented communities. E) using forest cover to escape from predators in their normal grassland habitat./ Answer: B
72 Which of the following is not a monomer
polymer pairing? A) monosaccharide/polysaccharide B) amino acid/protein C) triglyceride/phospholipid bilayer D) deoxyribonucleotide/DNA E) ribonucleotide/RNA/ Answer: C
