AP BIO EXAM QUESTIONS

what is the water potential for a NaCl in an open beaker that is 2M at 28 degrees celsius. Round to the nearest 10th

-100.1

At 20 degrees celsius, a cell with ψp=3 bars is in equilibrium with the surrounding .4M solution of sucrose in an open bearer. What is the solute potential of the cell? round to the nearest 100th

-12.74

Black fur mice (B) are dominant to brown fur mice (b). Short tail (T) are dominant to long tail (t). What fraction of the progeny of crosses between BbTtxBBtt will be expected to have black fur and long tails?

1/2

A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was 6 feet tall, and both the woman's parents were of average height. Achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive. They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?

100%

One liter of a solution of pH of 5 has how many more hydroxyl ions (OH-) than in one liter of a solution of pH 2?

1000

Cytosine makes up 38% of the nucleotides in a sample of DNA. Approximately what percentage of the nucleotides will be thymine?

12%

How many unique gametes can be produced through independent assortment by an individual with the genotype AaBbCcDdEE

16

What is the maximum number of covalent bonds an element with an atomic number of 7 can make with hydrogen?

3

A plant cell with ψs= -7.5 bars keeps a constant volume when immersed in an open beaker solution that has a ψs=-4.0 bars. What is the cell's ψp?

3.5

Given the parents AABBCc x AabbCc, assume simple dominance for each trait and independent assortment. What proportion of progeny will be expected to phenotypically resemble the first parent?

3/4

What is the pH of a solution with a hydroxyl ion concentration of 10⁻⁹ M?

5

A: Huntingtons disease B: Tay-sachs disease C: phenylketonuria D: hemophilia E: sickle cell disease This is caused by a dominant single gene defect and generally does not appear until the individual is 30-40 years of age

A

You have freshly prepared .1 M solution of glucose in water. Each liter of this solution contains how my glucose molecules? A) 6.02x10²² B) 3.01x10²³ C) 6.02x10²⁴ D) 12.04x10²³ E) 6.02x10²³

A) 6.02x10²²

A triploid cell contains three sets of 21 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 3 sets of 21 B) 63 chromosomes in 31 1/2 pairs C) 21 chromsome pairs and 21 unique chromosomes D ) 63 chromosomes, each with three chromatids

A) 63 chromosomes in 3 sets of 21

Which of the following is most likely to have small protein called ubiquitin attached to it? A) A cyclin that usually acts in G1, now that the cell is in G2 B) A cell surface proteins that requires transport from the ER C) An MRNA that is leaving the nucleus to be translated D) A regulatory protein that require sugar residues to be attached E) In mRNA produced by an egg cell that will be retained after fertilization

A) A cyclin that usually acts in G1, loud that the cell is in G2

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is A) AAA B) UUA C) TTT D) UUU E) Either UAA or TAA depending on first base wobble

A) AAA

In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of A) ATP, CO2 and ethanol B) ATP, CO2 and lactate C) ATP, NADH and pyruvate D) ATP, pyruvate, and oxygen E) ATP, pyruvate, and acetyl CoA

A) ATP, CO2 and ethanol

Functionally, which cellular location in the neurons "decision making site" as to whether or not an action potential will be initiated? A) Axon hillocks B) Dendritic membranes C) presynaptic membrane D) Axonal membranes

A) Axon hillocks

A mutation that inactivates the regulatory gene of a repressible operon in an E.Coli cell would result in A) Continuous transcription of the structural genes controlled by that regulator B) Complete inhibition of transcription of the structural gene controlled by that regulator C) Irreversible binding of the repressor to the operator D) In activation of RNA polymerize by alteration of its active site E) Continuous translation of the RNA because of alteration in its structure

A) Continuous transcription of the structural genes controlled by that regulator

Which of the following statements describes the results of this reaction: C₆H₁₂O₆+ 6O₂→ 6CO₂+6H₂O+ 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

A) C₆H₁₂O₆ is oxidized and O₂ is reduced

The process of cellular differentiation is a direct result of A) Differential gene expression B) Morphogenesis C) Cell division D) Apoptosis E) Differences in cellular genomes

A) Differential gene expression

The fact that plants can be cloned from somatic cells demonstrates that A) Differentiated cells retain all the genes of the zygote B) Genes are lost during differentiation C) The differentiated state is normally very unstable D) Differentiated cells contain masked mRNA E) Differentiation does not occur in plants

A) Differentiated cells retain all the genes of the zygote

Which of the following experimental procedures is most likely to hasten mRNA degradation in a eukaryotic cell? A) Enzymatic shortening of the poly a tail B) Removal of the five prime cap C) Methylation of C nucleotides D) Methylation of histones E) Removal of one or more exons

A) Enzymatic shortening of the poly a tail

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.

A) His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane

Muscle cells are stimulated by neurotransmitter is released from the synaptic terminals of A) Motor neuron axons B) Sensory neuron axons C) Motor neurons dendrites D) Sensory neurons dendrites

A) Motor neuron axons

Which of the following statements describes NAD+ A) NAD+ is reduced to NADH during both glycolysis and the citric acid cycle B) NAD+ has more chemical energy than NADH C) NAD+ is reduced by the action of hydrogenases D) NAD+ can donate electrons for use in oxidative phosphorylation E) in the absence of NAD+ glycolysis can function

A) NAD+ is reduced to NADH during both glycolysis and the citric acid cycle

Two fundamental concepts about the ion channels of a resting neuron are that the channels A) Open and close depending on stimuli, and or a specific as to which ion can traverse them B) Are always closed, but ions move closer to the channels during excitation C) Are always open, but the concentration gradients of ions frequently change D) Open response to stimuli, and then close simultaneously, in unison

A) Open and close depending on stimuli, and or a specific as to which ion can traverse them

Which of the following mechanisms is (are) used to coordinately control the expression of multiple, related genes in eukaryotic cells? A) Organization of the genes in the clusters, with local chromatin structure is influencing the expression of all the genes at once B) Which of the gene sharing a common control element, allowing several activators to turn on their transcription, regardless of their location in the genome C) Organizing the genes into large operons, allowing them to be transcribed as a single unit D) A Single repressor able to turn off several related genes E) Environmental signals that enter the cell and bind directly to their promoters

A) Organization of the genes in the clusters, with local chromatin structure is influencing the expression of all the genes at once

An earthworm without a statocyst would no be able to A) Orient with respect to gravity B) Respond to touch C) Sense light D) Hear

A) Orient with respect to gravity

A toxin that bind specifically to voltage gated sodium channels in axons would be expected to A) Prevent the depolarization phase of the action potential B) Have most of its effects on the dendritic region of a neuron C) Prevent the resting potential D) Increase the release of neurotransmitter molecules

A) Prevent the depolarization phase of the action potential

The activation of the parasympathetic branch of the autonomic nervous system is associated with A) Resting and digesting B) Flight or fight response C) Intensive aerobic exercise D) Release of epinephrine into the blood E) Increased metabolic rate

A) Resting and digesting

What does the operon model attempt to explain? A) The coordinated control of gene expression in bacteria B) Bacterial resistance to antibiotics C) How genes move between homologous regions of DNA D) The mechanism of viral attachment to a host cell E) Horizontal transmission of plant viruses

A) The coordinated control of gene expression in bacteria

There are 61 mRNA codon is that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that Some tRNAs have anticodons that recognize four or more different codons A) The rules for base pairing between the third base of a codon and tRNA are flexible B) The DNA codes for all 61 tRNAs but some are then destroyed C) Competitive exclusion forces some tRNAs to be destroyed by nucleases D) Many codons are never used, so the tRNA is that recognize them are dispensable

A) The rules for base pairing between the third base of a codon and tRNA are flexible

In both eukaryotes and prokaryotes, gene expression is primarily regulated at the level of A) Transcription B) Translation C) MRNA stability D) MRNA splicing E) Protein stability

A) Transcription

Why is it so important to amplify DNA fragments when studying genes? A) a gene may represent only a millionth of a cell's DNA B) DNA fragments are too small to use individually C) a clone required multiple copies of each genre per clone D) restriction enzymes cut DNA into fragments that are too smal

A) a gene may represent only a millionth of a cell's DNA

The MPF protein complex turns itself off by A) activating a process that destroys cyclin components B) activating the anaphase- promoting complex C) exiting the cell D) activating an enzyme that stimulates cyclin E) binding to chromatin

A) activating a process that destroys cyclin components

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

A) all of the electron transport proteins as well as ATP synthase

For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won't this experiment work? A) amino acids also have nitrogen atoms, thus radioactivity would not distinguish between DNA and proteins B) there is no radioactive isotope of nitrogen C) radioactive nitrogen has a half life of 100,000 years and the material would be too dangerous for too long D) Avery et al have already concluded that this experiment showed inconclusive results E) although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons, therefore they are more radioactive

A) amino acids also have nitrogen atoms, thus radioactivity would not distinguish between DNA and proteins

Which of the following is one of the ways 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 co transport of glucose and hydrogen E) by using active transport

A) by increasing the percentage of unsaturated phospholipids in the membrane

The individual with genotype AaBbCCDdEE can make many kinds of gametes. Which of the following is the major reason? A) different possible assortment of chromosomes into gametes B) segregation of maternal and paternal alleles C) the tendency for dominant alleys to segregate together D) recurrent mutations forming new alleles E) crossing over during prophase I

A) different possible assortment of chromosomes into gametes

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 the hydrogen atoms from saturated phospholipids C) enables the animals to add hydrogen atoms to unsaturated phospholipids D) makes the membrane less flexible, allowing it to sustain great pressures from within the cell E) makes the animal more susceptible to circulatory disorders

A) enables the membrane to stay fluid more easily when cell temperature drops

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 the results from the specific arrangement of matter E) energy cannot be transferred or transformed

A) energy cannot be created or destroyed

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 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 thus increase the rates of glycolysis and the citric acid cycle E) inhibit the enzyme and this increase the rate of glycolysis and the concentration of citrate

A) inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle

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 1/4 the DNA found and 1/2 the chromosomes as the originating cell C) it has the same number of chromosomes but each of them as different alleles than another cell from the same meiosis D) it is identical in content to another cell from the same meiosis E) it has had the chromosomes but twice the DNA of the originating cell

A) it has half the amount of DNA as the cell that began meiosis

You have a friend who last 7 kg of fat on a low carb diet. How did the fat leave her body? A) it was released as CO2 and H2O B) chemical energy 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

A) it was released as CO2 and H2O

When two atoms are equally electronegative, they will interact to form A) nonpolar covalent bonds B) hydrogen bonds C) van der waals interactions D) polar covalent bonds E) ionic bonds

A) nonpolar covalent bonds

Which is the smallest unity containing an entire human genome? A) one human somatic cell B) one human chromosome C) the entire human population D) one human gene E) all of the DNA of one human

A) one human somatic cell

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 the end of M to the end of G1? A) organelle density and enzymatic activity B) cell wall components and DNA C) organelle density and cell walls D) chlorophyll and DNA E) chlorophyll and cell walls

A) organelle density and enzymatic activity

In alcohol fermentation, NAD+ is regenerate from NADH during which of the following? A) reduction of acetaldehyde to ethanol B) oxidation of pyruvate to acetyl CoA C) reduction of pyruvate to form lactate D) oxidation of NAD+ in the citric acid cycle E) phosphorylation of ADP to form ATP

A) reduction of acetaldehyde to ethanol

Which of the flooding is an example of polygenetic inheritance? A) skin pigmentation in humans B) huntington's disease in humans C) the ABO blood group in humans D) white and purple flower colors in peas E) pink flowers in snapdragons

A) skin pigmentation in humans

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+

A) substrate- level phosphorylation

What is meant by the description of antiparallel regarding the stands that make up DNA? A) the 5' to 3' direction of one strand runs counter to the 3' to 5' direction of the other strand B) base pairing create unequal spacing between the two DNA strands C) one strand is positively charged and the other is negatively charged D) the twisting nature of DNA creates nonparallel strands E) one strand contains only purines and the other contains only pyrimidines

A) the 5' to 3' direction of one strand runs counter to the 3' to 5' direction of the other strand

Researchers began to study a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density dependent inhibition of anchorage dependence. What could they conclude right away? A) the cells show characteristics of tumors B) the cells originated in the nervous system C) the cells were originally derived from an elderly organism D) the cells are unable to form spindle microtubules E) the cells have altered series of cell cycle phases

A) the cells show characteristics of tumors

The mitochondrion, like the nucleus, has two or more membrane layers. How is the innermost of these layers different from that of the nucleus? A) the inner mitochondrial membrane is highly folded B) the two membranes are biochemically very different C) the space between the two layers of the nuclear membrane is larger D) the inner membrane of the mitochondrion is separated out into thylakoids E) the inner mitochondrial membrane is devoid of nearly all proteins

A) the inner mitochondrial membrane is highly folded

Consider the following experiment: A scientist determines that the number of dorsal spines of her experimental fish is determined by a single locus. She mates a fish with 1 dorsal spine with a fish of the same species with 2 dorsal spines. The mating produces ten fish, which all have 1 dorsal spine. Which of the following statements could NOT be true? A) the progeny fish are homozygous for "1 spine" allele B) "2 dorsal spines" is a recessive phenotype C) the progeny fish may be capable of producing progeny with only one spike D) the "2 spine" parent fish has a homozygous genotype at the dorsal spine locus E) 1 spine parent fish has a homozygous genotype at the dorsal spine locus

A) the progeny fish are homozygous for "1 spine" allele

Which of the following is true concerning cancer cells? A) when they stop dividing, they do so at random points of the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density dependent inhibition when growing in culture B) when they stop dividing, they do so at random points in the cell cycle C) when they stop dividing,they do so at random points in the cell cycle, and they are not subject to cell cycle controls D) they do not exhibit density dependent inhibition when growing in a culture E) they are not subject to cell cycle controls

A) when they stop dividing, they do so at random points of the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density dependent inhibition when growing in culture

A: Huntingtons disease B: Tay-sachs disease C: phenylketonuria D: hemophilia E: sickle cell disease Individuals with this disorder are unable to metabolize lipids, which affects proper brain development. Affected individuals usually die in early infancy

B

During a laboratory experiment, you discover that an enzyme- catalyzed reaction has a ∆G of -20kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction? A) -40kcal/mol B) -20kcal/mol C) 0kcal/mol D) +20kcal/mol E) +40kcal/mol

B) -20kcal/mol

The atomic number of each atom is given to the left of each of the following elements. Which of the following has the same valence as carbon (12/6 C) A) 10 Ne B) 14 Si C) 9 F D) 7 N

B) 14 Si

From its atomic number of 15, it is possible to predict that the phosphorus atom has A) 15 neutrons B) 15 protons and 15 neutrons C) 15 protons D) 8 electrons in its outermost electron shell E) 15 electrons

B) 15 protons and 15 neutrons

1. Formation of four new nuclei, each with half the chromosomes present in the parental nucleus 2. Alignment of tetrads at the metaphase plate 3. Separation of sister chromatids 4. Separation of the homologs; no uncoupling of the centromere 5. Synapsis; chromosomes moving to the middle of the cell in pairs 41) Which of the steps takes place in both mitosis and meiosis? A) 2, 3 and 5 B) 2 C) 5 D) 2 and 3 only E) 3

B) 2

What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms? A) 8 B) 6 C) 4 D) 2

B) 6

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product? A) A substitution of the first nucleotide of a GGG codon B) A deletion of two nucleotides C) A deletion of a codon D) A substitution of the third nucleotide in an ACC codon

B) A deletion of two nucleotides

In response to chemical signals, prokaryotes can do which of the following? A) Turn off translation of their mRNA B) Alter the level of production of various enzymes C) Increase the number and responsiveness of their ribosomes D) Inactivate their mRNA molecules E) Alter the sequence of amino acids in certain proteins

B) Alter the level of production of various enzymes

Alternative RNA splicing A) Is due to the presence or absence of particular snRNPs B) Can allow the production of proteins of different sizes and functions from a single mRNA C) Is a mechanism for increasing in the rate of transcription D) Increases the rate of transcription E) Can allow the production of similar proteins from different RNAs

B) Can allow the production of proteins of different sizes and functions from a single mRNA

A dog is following the scent of a jack rabbit. Which of the following accurately describes how the dog's brain integrates information for smell? A) Chemoreceptors in the brain send impulses for smell in the nasal cavity B) Chemoreceptor cells in the nasal cavity send impulses to the appropriate area of the brain C) Chemoreceptors on epithelial cells of the tongue send hormones to the appropriate area of the brain D) Receptors originating in the nose send action potentials to the motor regions of the brain

B) Chemoreceptor cells in the nasal cavity send impulses to the appropriate area of the brain

Major inhibitory neurotransmitter of the human brain is A) Acetylcholine B) GABA C) Epinephrine D) Nitric oxide

B) GABA

Food and water appetites are under the regulatory influence of the A) Cerebrum B) Hypothalamus C) Cerebellum D) Thalamus E) Medulla oblongata

B) Hypothalamus

A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N. Which of the following is a possible genotype for the mother? A) ii B) IAi C)IAIB D) IBIB E) IAIA

B) IAi

Transcription of the structural genes in inducible operon A) Occurs continuously in the cell B) Starts when the pathways substrate is present C) Starts when the pathways product is present D) Stops when the pathways product is present E) Does not result in the production of enzymes

B) Starts when the pathways substrate is present

The divisions of the nervous system that have antagonistic, or opposing, actions are the A) Central nervous system and peripheral nervous system B) Sympathetic and parasympathetic systems C) Forebrain and hindbrain D) Motor and sensory systems

B) Sympathetic and parasympathetic systems

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information we can reasonably infer that A) the concentration of hydrogen ions in solution Y is 1,000 times as great as the concentration of hydrogen ions in solution X B) The concentration of hydrogen ions in solution X is 1,000 times as great as the concentration of ions in solution Y C) The concentration of hydrogen ions in solution X is 30 times as great as the concentration of hydrogen ions in solution Y D) the concentration of hydrogen ions in solution X is 3 times as great as the concentration of hydrogen ions in solution Y

B) The concentration of hydrogen ions in solution X is 1,000 times as great as the concentration of ions in solution Y

The fastest possible conduction velocity of an action potential is observed in A) Thin myelinated neurons B) Thick, myelinated neurons C) Thin, nonmyelinated neurons D) Thick, nonmyelinated neurons

B) Thick, myelinated neurons

Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes? A) a cell that is secreting proteins B) a cell that is producing cytoplasmic enzymes C) a cell that is constructing its cell wall or extracellular matrix D) a cell that is digesting food particles E) a cell that is enlarging its vacuole

B) a cell that is producing cytoplasmic enzymes

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) an increase in the concentration of H₂CO₃ and a decrease in the concentration of HCO₃- B) a decrease in the concentration of H₂CO₃ and in increase 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 H₂CO₃ and H+

B) a decrease in the concentration of H₂CO₃ and in increase in the concentration of HCO₃-

They 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

B) accepting electrons at the end of the electron transport chain

Which of the following is likely to lead to an increase in the concentration of ATP in a cell? A) an increase in the cell's anabolic activity B) an increase in the cell's catabolic activity C) an increased influx of cofactor molecules D) an increased amino acid concentration E) the cell's increased transport of materials to the environment

B) an increase in the cell's catabolic activity

How do we describe the transformation in bacteria? A) the creation of a strand of RNA from a DNA molecule B) assimilation of external DNA into a cell C) the type of semiconservative replication shown in DNA D) the reaction of a strand of DNA from a RNA molecule

B) assimilation of external DNA into a cell

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, the color of which allows passage of only that wavelength. What color should she use to reduce overall light energy but still maximize plant growth? A) green B) blue C) orange D) Any color will work equally well.

B) blue

An animal cell lacking oligosaccharides on the external surface of its plasma member would likely be impaired in which function? A) transporting ions against an electrochemical gradient B) by increasing the percentage of cholesterol molecules in the membrane C) maintaining fluidity of the phospholipid bilayer D) attaching to the cytoskeleton E) establishing the diffusion barrier to charged molecules

B) by increasing the percentage of cholesterol molecules in the membrane

Which of the following correctly matches each of the inputs of the calvin cycle with its role in the cycle? A) carbon dioxide: high energy electrons: ATP: energy: NADPH: oxidation B) carbon dioxide: carbon: ATP: energy: NADPH: high energy electrons C) carbon dioxide: high energy electrons: ATP: carbon: NADPH: energy D) carbon dioxide: energy: ATP: carbon: NADPH: high energy electrons E) carbon dioxide: hydrogen: ATP: carbon: NADPH: energy

B) carbon dioxide: carbon: ATP: energy: NADPH: high energy electrons

Which bond of interaction would be difficult to disrupt when compounds are put into water? A) van der waals interaction B) covalent bond C) Hydrogen bond D) either covalent bond or ionic bond E) ionic bond

B) covalent bond

The chemical reaction for photosynthesis is 6CO₂+12H₂O+ light energy → C₆H₁₂O₆+ 6O₂+ 6H₂O If the input water is labeled with the radioactive isotope of oxygen (₁₈O), then the oxygen gas released as the reaction proceeds is labeled with ₁₈O. Which of the following is the most likely explanation? A) during the light reactions of photosynthesis, water is spilt, the hydrogen atoms combine with the CO2 and oxygen gas is released B) during the light reactions of photosynthesis, water is spilt, removing electrons and protons, and oxygen gas is released C) during the calvin cycle, water is spilt, regenerating NADPH from NADP+, and oxygen gas is released D) during the calvin cycle, water is split, the hydrogen atoms are added to intermediates of sugar synthesis, oxygen gas is released

B) during the light reactions of photosynthesis, water is spilt, removing electrons and protons, and oxygen gas is released

Why is each element unique and different from other elements with respect to its chemical properties? A) each element has a unique atomic mass B) each element has a unique number of protons C) each element has a unique number of neutrons D) each elements has different radioactive properties

B) each element has a unique number of protons

Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release energy? A) the covalent bonds in organic molecules are higher energy bonds than those in water and carbon dioxide B) electrons are being moved from atoms that have a lower affinity for electrons to atoms with a higher affinity for electrons 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

B) electrons are being moved from atoms that have a lower affinity for electrons to atoms with a higher affinity for electrons

During aerobic respiration, electrons travel downhill in which sequence? A) food--> citric acid cycle --> ATP --> NAD+ B) food --> NADH --> electron transport chin --> oxygen C) glucose --> pyruvate --> ATP --> oxygen D) glucose --> ATP --> electron transport chain --> NADH E) food --> glycolysis --> citric acid cycle --> NADH --> ATP

B) food --> NADH --> electron transport chin --> oxygen

Which process in eukaryotic cells will proceed normally whether oxygen is present or absent? A) electron transport B) glycolysis C) the citric acid cycle D) oxidative phosphorylation E) chemiosmosis

B) glycolysis

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 is found in the cytosol, does not involve oxygen and is present in most organisms C) it is found in prokaryotic cells but not in eukaryotic cells D) it relies on chemiosmosis with is a metabolic mechanism present only in the first cells- prokaryotic cells E) it requires the presence of membrane- enclosed cells found only in eukaryotic cells

B) it is found in the cytosol, does not involve oxygen and is present in most organisms

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 that pair have in common? A) they have nothing in common except that they are x shaped B) length, centromere position, staining pattern, and traits coded for by their genes C) length and position of the centromeres only D) length, centromere position, and staining pattern only E) length, centromere position, staining pattern and DNA sequences

B) length, centromere position, staining pattern, and traits coded for by their genes

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.

B) loses electrons and loses potential energy

It is possible to prepare vesicles from portions of the inner membrane of the mitochondrial components. 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

B) oxidative phosphorylation

Englemann placed a strong of the filamentous alga Cladophora onto a slide, to which he added aerobic bacteria. Under the condense of white light, microscopic observation revealed that the bacteria were evenly distributed along the length of the alga filament. The beam of white light was broken down into its component wavelengths, which extended across the spectrum from the blue end to the red end. It was the focused on the alga. Englemann noticed that the bacteria migrated to and accumulated around the portions of the alga filament that were positioned within the zones of the blue and red wavelengths of the light. The process that was investigated by the experiment was A) fermentation B) photosynthesis C) cellular respiration D) plasmolysis E) bacteria adaption

B) photosynthesis

Which of the following statements best describes the relationship between photosynthesis and respiration? A) respiration is the exact reversal of the biochemical pathways of photosynthesis B) photosynthesis stores the energy in complex organic molecules and respiration releases 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

B) photosynthesis stores the energy in complex organic molecules and respiration releases

Carbohydrate-synthesizing reactions of photosynthesis directly require A) light B) products of the light reactions C) darkness D) O2 and H2O E) chlorophyll and CO2

B) products of the light reactions

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 acidic and carbonate concentrations will decrease C)there will be no change in the pH of seawater because carbonate will turn into bicarbonate D) Seawater will become more acidic and carbonate concentrations will increase

B) seawater will become more acidic and carbonate concentrations will decrease

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

B) small and hydrophobic

Why is it important to know what microscopy method was used to prepare images you wish to study> A) so that you can judge whether the images you are seeing are of cells or organelles B) so that you can make a judgement about the likelihood of artifacts having been introduced in preparation C) so that you can decide whether the image is actually of the size described D) so that you ca know whether to view the image in color or not E) so that you can interpret the correct biochemical process that is occurring in the cells as you are viewing them

B) so that you can make a judgement about the likelihood of artifacts having been introduced in preparation

Hemophilia is a sex-linked recessive trait. A male hemophiliac and a phenotypically normal female have a girl that is hemophiliac. All of the following statements are correct except A) the daughter inherited a recessive gene from each parent B) the daughter inherited a dominant allele from her mother C) the mother is a carrier of hemophilia D) the genotype of the mother is XH Xh E) the genotype of the father is XhY

B) the daughter inherited a dominant allele from her mother

The difference between ATP and the nuleoside triphosphates used during DNA synthesis is that A) ATP contains three energy bonds; the nucleoside triphosphate have two B) the nuceloside triphosphate have they sugar deoxyribose; ATP has the sugar ribose C) ATP is found only in human cells; the nucleoside triphosphate are found in all animals and plant cells D) the nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups

B) the nuceloside triphosphate have they sugar deoxyribose; ATP has the sugar ribose

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 are unable to transform energy E) Life does not obey the first law of thermodynamics

B) the organism ultimately must obtain all of the necessary energy for life from its environment

In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in a 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 number of enzymes in the fraction E) the presence or absence of lipids in the component

B) the size and weight of the component

How many molecules of carbon dioxide would be produced by five turns of the citric acid cycle? A) 2 B) 5 C) 10 D) 12 E) 60

C) 10

This binds to a site in the DNA far from the promoter to stimulate transcription: A) Enhancer B) Promoter C) Activator D) Repressor E) Terminator

C) Activator

Altering patterns of gene expression in prokaryotes would most likely serve the organism survival in which of the following ways? A) Organizing gene expression so that genes are expressed in a given order B) Allowing each gene to be expressed an equal number of times C) Allowing the organism to adjust to changes in environmental conditions D) Allowing young organisms to respond differently from more mature organisms E) Allowing environmental changes to alter the prokaryotes genome

C) Allowing the organism to adjust to changes in environmental conditions

Tumor suppressor genes A) Are frequently over express in cancerous cells B) Are cancer- causing genes introduced into cells by viruses C) Can encode proteins that promote DNA repair or cell to cell adhesion D) Often encode proteins that stimulate the cell cycle E) All of the above

C) Can encode proteins that promote DNA repair or cell to cell adhesion

In the human retina A) Cone cells are more sensitive than rod cells to light B) Rod cells are most highly concentrated in the center of the retina C) Cone cells can detect color, but rod cells cannot D) Rod cells require higher illumination for stimulation than do cone cells E) Cone cells, but not rod cells, have a visual pigment

C) Cone cells can detect color, but rod cells cannot

The activity of acetylcholine in a synapse is terminated by its A) Diffusion across the presynaptic membrane B) Diffusion across the postsynaptic membrane C) Degradation by a hydrolytic enzyme on the postsynaptic membrane D) Active transport from the postsynaptic membrane

C) Degradation by a hydrolytic enzyme on the postsynaptic membrane

A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) already in the ribosome. Where does tRNA (#2) move to after this bonding of lysine to the polypeptide? A) A site B) P site C) E Site D) Directly to the cytosol E) Exit tunnel

C) E Site

If a modern electron microscope can resolve biological images to the nanometer level, as opposed to the best light microscope, this is due to which of the following? A) the focal length of the electron microscope is significantly longer B) contrast is enhanced by staining with atoms of heavy metals C) Electron beams have much shorter wavelengths than visible light D) the electron microscope has much greater ration of image size to real size E) the electron microscope cannot image whole cells at one time

C) Electron beams have much shorter wavelengths than visible light

If an atom of sulfur (atomic number 16) were allowed to react with atoms of hydrogen (atomic number 1), which of the following molecules would be formed? H A) H-S-H H B) H-S-H H C) H-S-H D) S-H E) H=S=H

C) H-S-H

If you were to observe the activity of methylated DNA, you would expect it to A) Be replicating nearly continuously B) Be unwinding in preparation for protein synthesis C) Have turned off or slow down the process of transcription D) Be very actively transcribed or translated E) Induce protein synthesis by not allowing repressor's to bind to it

C) Have turned off or slow down the process of transcription

A mutation in this section of the DNA could influence the binding of RNA polymerase to the DNA: A) Operon B) Inducer C) Promoter D) Repressor E) Corepressor

C) Promoter

The autonomic nervous system A) Integrates sensory inputs to the brain B) Carries signals to and from skeletal muscles C) Regulates the internal environment of the body D) is mostly voluntary E) Is part of the central nervous system

C) Regulates the internal environment of the body

Sensory perception is A) The reception of a stimulus by a sensory cell B) The conversion of stimulus energy into a receptor potential by a sensory receptor or sensory neuron C) The interpretation of a stimulus according to the region of the brain that receives the nerve impulse D) The amplification and transmission of sensory data to the CNS E) Emotional response to a stimulus

C) The interpretation of a stimulus according to the region of the brain that receives the nerve impulse

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 is hypotonic compared to the cells. C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells. D) The patient's red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells. E) The patient's red blood cells will burst because the blood fluid is hypertonic compared to the cells.

C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells

In a simple synapse, neurotransmitter chemicals are released by A) Ducts on the smooth endoplasmic reticulum B) Cell bodies C) The presynaptic membrane D) Axon hillocks

C) The presynaptic membrane

A researcher has arrived at a method to prevent gene expression from drosophila embryonic genes. The following questions assume that he is using this method. The researcher in question measures the amount of new polypeptide production in embryos from 2 to 8 hours following fertilization and the results show a steady and significant rise in polypeptide concentration over that time. The researcher concludes that A) His measurements skills must be faulty B) The results are due to building new cell membranes to compartmentalize dividing nuclei. C) The resulting new polypeptides are due to translation of maternal mRNAs D) The new polypeptides were in active and not measurable until fertilization E) Polypeptides were attached to egg membranes until this time

C) The resulting new polypeptides are due to translation of maternal mRNAs

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. 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

C) The water level is higher in side A than in side B

A cell that remains entirely flexible in its development possibilities is said to be A) Differentiated B) Determined C) Totipotent D) genomically equivalent E) epigenetic

C) Totipotent

What type of bond or interaction is responsible for the gecko's ability to climb the whiteboard in a classroom? A) covalent bonds B) ionic bonds C) Van der Waal interactions D) ionic bonds and van der waal interactions E) hydrogen bonds

C) Van der Waal interactions

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 cell to withstand enzymatic digestion 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

C) a change in the shape of the nucleus

If plants are grown for several days in an atmosphere containing ¹⁴CO₂ in place of ¹²CO₂, one would expect to find A) very little radioactivity in the growing leaves B) large amounts of radioactive water released from the stomates C) a large increase in ¹⁴C in the starch stored in the roots D) a large decrease in the rate of carbon fixation in guard cells E) an increase in the activity of RuBP carboxylase in the photosynthetic cells

C) a large increase in ¹⁴C in the starch stored in the roots

When biologists wish to study the internal ultrastructure of cells, they most likely would use A) a light microscope B) a scanning electron microscope C) a transmission electron microscope D) A and B E) B and C

C) a transmission electron microscope

Where do catabolic products of fatty acid breakdown enter into the citric acid cycle? A) pyruvate B) malate of fumarate C) acetyl CoA D) succinyl CoA

C) acetyl CoA

In humans, clear gender differentiation occurs, not at fertilization, but after the second month of gestation. What is the first event of this differentiation? A) formation of testosterone in male embryos B) activation of SRY in females and feminization of the gonads C) activation of SRY in male embryos and masculinization of the gonads D) formation of estrogen in female embryos E) anatomical differentiation of a penis in the male embryos

C) activation of SRY in male embryos and masculinization of the gonads

Our understanding of mental illness has been most advanced by discoveries involving the A) evolution of the telencephalon. B) nature of the blood-brain barrier. C) chemicals involved in brain communications, D) degree of convolutions in the brain's surface.

C) chemicals involved in brain communications

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.

C) contributes to the membrane potential

Halobacterium has a photosynthetic membrane that appears purple. Its photosynthetic action spectrum is the inverse of the action spectrum for green plants. (That is, the Halobacterium action spectrum has a peak where the green plant action spectrum has a trough.) 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

C) green and yellow

Which type of bond must be broken for water to vaporize? A) both hydrogen bonds and ionic bonds B) both polar covalent bonds hydrogen bonds C) hydrogen bonds D) polar covalent bonds E) ionic bonds

C) hydrogen bonds

In both photosynthesis and respiration, a electrochemical proton gradient drives chemiosmosis. What establishes the electrochemical grander across a membrane to provide energy for ATP production? A) the electron transport system provided with hydrogen ions B) hydrogen ions naturally collect on the outside of the organelle membrane C) hydrogen ions are pumped across the membrane by carrier proteins of the electron transport chain D) active transport of hydrogen ions causes the unequal distribution of ions on the two sides of the membrane

C) hydrogen ions are pumped across the membrane by carrier proteins of the electron transport chain

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

C) isotonic

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes, and about 17 times that of the cell's plasma membrane. What purpose must this serve? A) it allows for increased rate of glycolysis B) It allows for 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

C) it increases the surface for oxidative phosphorylation

Which of the following statements is correct about diffusion? A) its 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 a region of higher concentration E) it requires integral proteins in the cell membrane

C) it is a passive process in which molecules move from a region of higher concentration to a region of lower concentration

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication? A) it synthesizes RNA nucleotides to make a primer B) it catalyzes the lengthening of the telomeres C) it joins okazaki fragments together D) it stabilized the unwound parental DNA E) it unwinds the parental double helix

C) it joins okazaki fragments together

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) A and B E) B and C

C) light microscopy allows one to view dynamic processes in living cells

Males areole often affected by sex linked traits than females because A) male hormones such as testosterone often alter the affects of motions on the X chromosome B) mutations on the Y chromosome often worsen the effects of the X chromosome C) males are hemizygous for the X chromosome D) female hormones such as estrogen often compensate for the effects of motions on the X chromosome E) X chromosomes in males generally have more mutations than x chromosomes in females

C) males are hemizygous for the X chromosome

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? A) anaphase B) interphase C) metaphase D) telophase E) prophase

C) metaphase

In E. coli, there is a mutation in a gene called dnaB that alters the helices that normally acts as the origin. Which of the following would you expect as a result of this mutation? A) no proofreading to occur B) the DNA will supercoil C) no replication fork will be formed D) replication will require a DNA template from another source E) replication will occur via RNA polymerase alone

C) no replication fork will be formed

Hydrophobic substances such as vegetable oil are A) nonpolar substances that have an attraction for water molecules B) polar substances that repel water molecules C) nonpolar substances that repel water molecules D) polar substances that have an affinity for water E) charged molecules that hydrogen- bond with water molecules

C) nonpolar substances that repel water molecules

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

C) on the inside surface of the vesicle

Which of these is a karyotype? A) a display of all cell types in an organism B) a natural cellular arrangement of chromosomes in the nucleus C) organized images of the cell's chromosomes D) the appearance of an organism E) a display of the cell's mitotic stages

C) organized images of the cell's chromosomes

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) none of the above

C) oxidize NADH to NAD+

When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes A) dehydrogenated B) hydrogenated C) oxidized D) reduced E) an oxidizing agent

C) oxidized

Englemann placed a strong of the filamentous alga Cladophora onto a slide, to which he added aerobic bacteria. Under the condense of white light, microscopic observation revealed that the bacteria were evenly distributed along the length of the alga filament. The beam of white light was broken down into its component wavelengths, which extended across the spectrum from the blue end to the red end. It was the focused on the alga. Englemann noticed that the bacteria migrated to and accumulated around the portions of the alga filament that were positioned within the zones of the blue and red wavelengths of the light. The difference in conditions of the alga in the blue and red wavelengths of light might due to the presence of A) carbon dioxide B) water C) oxygen D) carbohydrates E) protein

C) oxygen

To visualize and identify meiotic cells at metaphase with a microscope, what would you look for? A) an uninterrupted spindle array B) the synaptonemal complex C) pairs of homologous chromosomes all aligned at the cell's center D) sister chromatids of a replicated chromosome grouped at the poles E) individual chromosomes at the cell's center

C) pairs of homologous chromosomes all aligned at the cell's center

Which of these are not embedded in the lipid bilayer at all? A) transmembrane protein B) integral protein C) peripheral protein D) integrins E) glycoproteins

C) peripheral protein

When a potassium ion moves from the soil into the vacuole of a cell on the surface of the 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- tonoplast B) secondary cell wall- plasma membrane- primary cell wall- cytoplasm- tonoplast C) primary cell wall- plasma membrane- cytoplasm- tonoplast D) primary cell wall- plasma membrane- tonoplast- cytoplasm- vacuole E) tonoplast- primary cell wall- plasma membrane- cytoplasm

C) primary cell wall- plasma membrane- cytoplasm- tonoplast

movement of the chromosomes during anaphase would be most affected by a drug that prevents A) nuclear envelope breakdown B) formation of the cleavage furrow C) shortening of microtubules D) cell wall formation E) elongation of microtubules

C) shortening of microtubules

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

C) the lysosome

A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI. The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mixture is incubated for several hours, exposed to DNA ligase, and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics. Bacteria that do not take up any plasmids would grow on which media? A) the nutrient broth and the tetracycline broth B) the nutrient broth and the ampicillin broth C) the nutrient broth only D) all three broths

C) the nutrient broth only

Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight. This occurs because their cells are impaired in what way? A) they cannot undergo mitosis B) they connect exchange DNA with other cells C) they cannot repair thymine dimers caused by UV radiation D) They do not recombine homologous chromosomes during meiosis E) they cannot replicate DNA

C) they cannot repair thymine dimers caused by UV radiation

in cats, black fur is caused by an X-linked allele, the other alleles at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross between a black female and an orange male? A) tortoiseshell females, tortoiseshell males B) black females, orange males C) tortoiseshell females, black males D) orange females, black males E) orange females, orange males

C) tortoiseshell females, black males

One difference between carbon-12 and carbon-14 is that carbon-14 has A) two more electrons and two more neutrons than carbon-12 B) two more protons than carbon-12 C) two more neutrons that carbon-12 D) two more electrons than carbon-12 E) two more protons and two more neutrons than carbon-12

C) two more neutrons that carbon-12

An organism that lacks integration centers A) cannot receive stimuli. B) can expected to lack myelinated neurons. C) will not be able to interpret stimuli D) will not have nervous system.

C) will not be able to interpret stimuli

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, so the cells must keep the calcium concentration quite low. Muscle cells also transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a muscle cell cytosol has a free calcium ion concentration of 10⁻⁷ in a resting cell, while the concentration in the SR can be 10⁻², then how is the ATPase acting? A) the ATP must be powering an inflow of calcium from the outside of the cell into the SR B) ATP must be transferring Pi into 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) the calcium ions must be diffusing backing into the SR along the concentration gradient E) the route of calcium ions must be from SR to the cytosol to the cell's environment

C)ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient

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 1.0 M glucose B) 1 L of .5 M NaCl C) 1 L of .5 M glucose D) 1 L of 1.0 M NaCl E) 1 L of 1.0 M NaCl and 1.L of 1.0 glucose will be equal

D) 1 L of 1.0 M NaCl

Cinnabar eyes is a sex linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild type male, what percentage of the F1 males would have cinnabar eyes? A) 25% B) 50% C) 75% D) 100% E) 0%

D) 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. 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

D) ATP synthase, in whole or in part

A cell lacking the ability to make and secrete glycoproteins would most likely be defiance in its A) nuclear DNA B) extracellular matrix C) golgi apparatus D) B and C only E) B only

D) B and C only

Organelles other than the nucleus that contain DNA include A) ribosomes B) mitochondria C) chloroplasts D) B and C only E) A, B and C

D) B and C only

Which of the following crosses most likely produced the following results: 54 blue two horned lizards, 18 blue one horned lizards, 18 green two horned lizards, and 6 green one horned lizards A) BbxBb B) BBHhxBbHh C) BBHHxbbhh D) BbHhxBbHh

D) BbHhxBbHh

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? A) MPF B) protein kinase C) cyclin D) Cdk E) PDGF

D) Cdk

Two potential devices that eukaryotic cells use to regulate transcription are A) DNA methylation and histone amplification B) DNA amplification and histone methylation C) DNA acetylation and methylation D) DNA methylation and histone acetylation E) Histone amplification and DNA acetylation

D) DNA methylation and histone acetylation

Genomic Imprinting, DNA methylation, and histone acetylation are all examples of A) Genetic mutation B) Chromosomal rearrangements C) Karyotypes D) Epigenetic phenomena E) Translocation

D) Epigenetic phenomena

Muscle cells and nerve cells in one species of animal owe their differences in structure to A) Having different genes B) Having different chromosomes C) Having different genetic codes D) Having different genes expressed E) Having unique ribosomes

D) Having different genes expressed

Which of the following would be regarded as compounds? A) H₂0 and O₂ B) CH₄ and O₂, but not H₂O C) H₂O, O₂, and CH₄ D) H₂O and CH₄ but not O₂ E) O₂ and CH₄

D) H₂O and CH₄ but not O₂

Neural transmission across a mammalian synapse accomplished by A) The movement of calcium ions from the presynaptic into the postsynaptic neuron B) Impulses traveling as electrical current across the synapse C) The movement of sodium and potassium ions from the presynaptic neuron into the postsynaptic neuron D) Impulse is causing the release of a chemical signal and it's diffusion across the synapse

D) Impulse is causing the release of a chemical signal and it's diffusion across the synapse

One hereditary disease in humans, called XP, makes homozygous individuals exceptionally susceptible to UV-induced mutation damage in the cells of exposed tissue, especially skin. Without extraordinary avoidance of sunlight exposure, patients soon succumb to numerous skin cancers. Which of the following best describes this phenomenon? A) Inherited cancer taking a few years to be expressed B) Embryonic or fetal cancer C) Inherited predisposition to mutation D) Inherited inability to repair UV induced mutation E) Susceptibility to chemical carcinogens

D) Inherited inability to repair UV induced mutation

What is the function of the release factor (RF)? A) It releases the amino acid from us tRNA to allow the amino acid to form a peptide bond B) it releases the ribosome from the ER to allow polypeptides into the cytosol C) It separates tRNA in the A site from the growing polypeptide D) It binds to the stop codon in the a site in place of a tRNA and as a water molecule to the end of the polypeptide

D) It binds to the stop codon in the a site in place of a tRNA and as a water molecule to the end of the polypeptide

A researcher has arrived at a method to prevent gene expression from drosophila embryonic genes. The following questions assume that he is using this method. The researcher continues to study the reactions of the embryo to these new proteins and you hypothesize that he is most likely to see which of the following (while embryonic genes are still not being expressed)? A) The cells begin to differentiate B) The proteins are evenly distributed throughout the embryo C) Larval features begin to make their appearance D) Spatial axes (anterior and posterior) begin to be determined E) The embryo begins to lose sales due to apoptosis from no further gene expression

D) Spatial axes (anterior and posterior) begin to be determined

When is stimulus is applied to a receptor in the skin, an action potential is propagated along a neuron to the brain, where another signal is sent back to the muscle for response. Which of the following best describes what occurs when the action potential reaches a chemical synapse at the end of an axon? A) The action potential jumps from one acts on to the next connecting axon B) The action potential travels through the synapse to the next connecting dendrite C) The action potential jumped the synapse to the next connecting dendrite D) The action potential causes a release of neurotransmitters that travel across the synapse

D) The action potential causes a release of neurotransmitters that travel across the synapse

What was the most significant conclusion that Mendel drew from his experiments with pea plants? A) Genes are composed of DNA. B) An organism that is homozygous for many recessive traits is at a disadvantage. C) There is considerable genetic variation in garden peas. D) Traits are inherited in discrete units, and are not the results of "blending." E) Recessive genes occur more frequently in the F₁ generation than do dominant ones.

D) Traits are inherited in discrete units, and are not the results of "blending."

In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must included in addition to the coding exons of the gene? A) eukaryotic polymerases B) eukaryotic ribosomal subunits C) eukaryotic tRNAs D) a bacterial promoter sequence

D) a bacterial promoter sequence

Which of the following is an example of potential rather than kinetic energy? A) a boy mowing grass B) water rushing over Niagara falls C) a firefly using light flashes to attract a mate D) a food molecule made up of energy rich macromolecules E) an insect foraging for food

D) a food molecule made up of energy rich macromolecules

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) a plant but not an animal D) a plant or an animal

D) a plant or an animal

All female mammals have on active X chromosome per cell instead of 2. What causes this? A) attachment of methyl groups to the X chromosome B) activation of the Barr gene on one x chromosome, which then becomes inactive C) inactivation of the XIST gene on the X chromosome derived from the male parent D) activation of the XIST gene on the x chromosome that will become the Barr body E) crossing over between XIST gene on X chromosome and a related gene on the autosome

D) activation of the XIST gene on the x chromosome that will become the Barr body

Electrons can 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 closer to the nucleus B) the atom may become a radioactive isotope C) the atom would become a positively charged ion, or cation, and become and become a radioactive isotope D) an electron may move to an electron shell farther away from the nucleus

D) an electron may move to an electron shell farther away from the nucleus

Which of the following is true of the evolution of cell membranes? A) cell membranes have stopped evolving now that they have fluid mosaics B) cell membranes cannot evolve if proteins don't C) The evolution of cell membranes is driven by the evolution of glycoproteins and glycoplipids D) as populations of organisms evolve, different properties of their cell membranes are selected for or against E) An individual organism selects its preferred type of cell membrane for particular functions

D) as populations of organisms evolve, different properties of their cell membranes are selected for or against

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, while 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

D) chloroplasts and mitochondria

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? A) DNA synthesis B) spindle attachment to the kinetochores C) spindle formation D) cleavage furrow formation and cytokinesis E) cell elongation during anaphase

D) cleavage furrow formation and cytokinesis

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) cytoskeletons E) cellulose fibers in the cell

D) cytoskeletons

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 ATP synthase pumping hydrogen ions against their concentration gradient D) energy released from movement of protons through the ATP synthase E) no external source of energy is required because the reaction is exergonic

D) energy released from movement of protons through the ATP synthase

Human produce skin cells by mitosis and gametes by meiosis. The nuclei of the skin cell produced by mitosis will have A) twice as much DNA as the nuclei of gametes produced by meiosis B) four times as much DNA as the nuclei of gametes produced by meiosis C) the same amount of DNA as the nuclei of gametes produced by meiosis D) half as much DNA as the nuclei of gametes produced by meiosis

D) half as much DNA as the nuclei of gametes produced by meiosis

A molecule that is phosphorylated A) has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate B) has a decreased chemical reactivity; it is less likely to provide energy for cellular work C) has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate D) has an increased chemical reactivity; it is primed to do cellular work E) has less energy than before its phosphorylation and therefore less energy for cellular work

D) has an increased chemical reactivity; it is primed to do cellular work

The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside world 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

D) integrins

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve in the cell? A) it is released in excretory waste B) it can only be used to regenerate ATP C) it can be added to water and excreted as a liquid D) it can be added to other molecules in order to activate them E) it can enter the nucleus to affect gene expression

D) it can be added to other molecules in order to activate them

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 lose to the environment E) it is transported to specific organs such as the brain

D) it is lose to the environment

Energy released by the electron transport chain is used to pump H+ ions into which location? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix

D) mitochondrial intermembrane space

The chemical reactions involved in the respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic cells the ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely to occur in prokaryotic respiration? A) in the cytoplasm B) on the inner mitochondrial membrane C) on the endoplasmic reticulum D) on the inner plasma membrane E) on the inner nuclear envelope

D) on the inner plasma membrane

A covalent chemical bond is one in which A) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms. B) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atoms C) electrons are removed from one atom and transferred to another atom so that two atoms become oppositely charged D) 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 two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms

All of the following statements are related to the light reaction of photosynthesis. All of these are true except A) photosynthesis is initiated by the absorption of light by chlorophyll molecules B) the chlorophyll molecules of the illuminated chloroplasts are raised to a higher energy level C) the "excited" electrons return to their normal energy levels if not captured in the reaction D) some of the energy of the "excited" electron is used to spilt carbon dioxide E) the biochemical activities of the light reaction occur in the grana

D) some of the energy of the "excited" electron is used to spilt carbon dioxide

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 C) all ducts such as those from salivary or sebaceous glands D) sperm, larynx, and trachea E) egg cells, uterus, kidneys

D) sperm, larynx, and trachea

Many mammals control their body temperatures by sweating. Which property of water is most directly responsible for the ability of sweat to lower the body temperature? A) water's high surface tension B) water's ability to dissolve molecules in the air C) water's change in density when it condenses D) the absorption of heat by the breaking of hydrogen bonds E) the release of heat by the formation of hydrogen bods

D) the absorption of heat by the breaking of hydrogen bonds

Which of the following can be determined directly from X-ray diffraction photographs of crystalized DNA? A) the frequency of A vs T nucleotides B) the rate of replication C) the bond angles of subunits D) the diameter of a helix E) the sequence of nucleotides

D) the diameter of a helix

The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation 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 difference in H+ concentrations on opposite sides of the inner mitochondria membrane E) the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP

D) the difference in H+ concentrations on opposite sides of the inner mitochondria membrane

What are lipids and proteins free to move laterally in membranes? A) the interior of the membrane is filled with liquid water B) there are no covalent bonds between lipids and proteins 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

D) there are only weak hydrophobic interactions in the interior of the membrane

Feather color in budgies is determined by two different genes, Y and B, one for pigment on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. Two blue budgies were crossed. Over the years, they produced 22 offspring, 5 of which were white. What are the most likely genotypes for the two blue budgies? A) yyBB and yybb B) yyBb and yybb C) yyBB and yyBB D) yyBb and yyBb E) yyBB and yyBb

D) yyBb and yyBb

At the beginning of the century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. There was surprise expressed by many that the number of protein coding sequences is much smaller than they had expected. Which of the following accounts for most of the rest? A) Junk DNA that serves no possible purpose B) rRNA and tRNA coding sequences C) DNA that is translated directly without being transcribed D)Non-protein coding DNA that is transcribed into several kinds of small RNAs with biological function E) Non-protein coding DNA that is transcribed into several kinds of small RNAs without biological function

D)Non-protein coding DNA that is transcribed into several kinds of small RNAs with biological function

A: Huntingtons disease B: Tay-sachs disease C: phenylketonuria D: hemophilia E: sickle cell disease Substation of the "wrong" amino acid in the hemoglobin protein results in this disorder

E

The regulatory centers for the respiratory and circulatory systems are found in the A) Cerebrum B) Cerebellum C) Thalamus D) Hypothalamus E) Medulla oblongata

E) Medulla oblongata

The light reactions of photosynthesis generate high- energy electrons, which end up in____________. They also produce___________ and _______________. A) ATP, NADPH, Oxygen B) oxygen, sugar, ATP C) chlorophyll, ATP, NADPH D) water, sugar, oxygen E) NADPH, ATP, oxygen

E) NADPH, ATP, oxygen

Using the list of choices below for the following question I. helicase II. DNA polymerase III III. ligase IV. DNA polymerase I V. primase Which of the enzymes synthesizes short segments of RNA? A) I B) II C) III D) IV E) V

E) V

the golgi apparatus has a polarity to its structure and function. Which of the following statement 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 the 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 cistern 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 describe polar characteristics of the golgi function

E) all of the above describe polar characteristics of the golgi function

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

E) an endoplasmic reticulum

Where does glycolysis take place? A) mitochondrial matrix B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial inter membrane E) cytosol

E) cytosol

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. It should be possible to reconstitute the abilities of the vesicles if which of the following is added? A) cytochromes B) extra NADH C) a second membrane surface D) more electrons E) intact ATP synthase

E) intact ATP synthase

A mycoplasma is an organism with a diameter between .1 and 1.0 μm. What does its size tell you about how it might be classified? A) it must be a single cell protists B) it must be a single cell fungus C) it could be almost any type of bacterium D) it could be a typical virus E) it could be a very small bacterium

E) it could be a very small bacterium

An organism is discovered that consumes a considerable amount of sugar, yet does not gain much weight when denied air. Curiously, the consumption of sugar increases as air is removed from the organismʹs environment, but the organism seems to thrive even in the absence of air. When returned to normal air, the organism does fine. Which of the following best describes the organism? A) it must use a molecule other than oxygen to accept electrons from the electron transport chain B) it is a normal eukaryotic organism C) the organism obviously lacks the citric acid cycle and electron transport chain D) it is an anaerobic organism E) it is a facultative anaerobe

E) it is a facultative anaerobe

Why is glycolysis described as having an investment phase and a pay off phase? A) it both splits 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 the forms a net increase in ATP

E) it uses stored ATP and the forms a net increase in ATP

Centrioles, cilia, flagella and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probably hypothesis? A) disruption of one of these structures should necessarily disrupt each of the others as well 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 structures D) evolution of motility, of cells or parts of cells, must have occurred only once E) natural selection for motility must select for microtubule arrays in circular patterns.

E) natural selection for motility must select for microtubule arrays in circular patterns.

What is the change in free energy of a system at chemical equilibrium? A) slightly increasing B) greatly increasing C) slightly decreasing D) greatly decreasing E) no net change

E) no net change

Which of the following represents the order of increasingly higher levels of organization of chromatin? A) nucleosome, looped domain, 30 nm chromatin fiber B) 30 nm chromatin fiber, nucleosome, lopped domain C) lopped domain, 30 nm chromatin fiber, nucleosome D) looped domain, nucleosome, 30 nm chromatin fiber E) nucleosome, 30 nm chromatin fiber, looped domain

E) nucleosome, 30 nm chromatin fiber, looped domain

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

E) nucleus, mitochondria, ribosomes

Which of the following contains enzymes that transfer hydrogen from various substrates to oxygen? A) lysosome B) vacuole C) mitochondria D) golgi apparatus E) peroxisome

E) peroxisome

Englemann placed a strong of the filamentous alga Cladophora onto a slide, to which he added aerobic bacteria. Under the condense of white light, microscopic observation revealed that the bacteria were evenly distributed along the length of the alga filament. The beam of white light was broken down into its component wavelengths, which extended across the spectrum from the blue end to the red end. It was the focused on the alga. Englemann noticed that the bacteria migrated to and accumulated around the portions of the alga filament that were positioned within the zones of the blue and red wavelengths of the light. A probably reason for the clustering of the bacteria in the red and blue portions of the spectrum is A) the bacteria prefer to feed in red and blue light B) the bacteria prefer red and blue colors to green and yellow colors C) the bacteria clustered at the red and blue ends of the spectrum by chance only D) the bacteria exhibit a positive red and blue phototropism E) the bacteria require some substance found in greater abundances in the red and blue areas of light

E) the bacteria require some substance found in greater abundances in the red and blue areas of light

Mendel accounted for the observation that traits that had disappeared in the F1 generation reaper in the F2 generation by proposing that A) the mechanism controlling the appearance of traits was different between the F1 and F2 generations B) the traits were lost in the F1 due to dominance in parental traits C) new mutations were frequently generated in F2 progeny, "reinventing" traits that had been lost in the F1 D) members of the F1 generation only had one allele for each trait, but members of the F2 generation had two for each trait E) traits can be dominant or recessive, and there recessive traits were obscured by the dominant ones in the F1

E) traits can be dominant or recessive, and there recessive traits were obscured by the dominant ones in the F1

Which of the following takes place as a lake freezes over for winter? A) a specific heat of the water in the lake decreases B) molecular collisions in the lake increase C) water molecules at 4 degrees celsius rise to the surface D) kinetic energy of the lake increases E) water becomes less dense due to the failure of H bonds to form and reform

E) water becomes less dense due to the failure of H bonds to form and reform