AP BIO EXAM
A photosynthetic organism would be represented by which species? A A B B C C D D E E
A
A researcher proposes that the spawning behavior takes place when the nighttime tides are highest during the month. Which of the following pieces of evidence would best support the researcher's claim? A Grunion spawning occurs every two weeks during the spawning season. B Grunion spawning occurs when nighttime illumination levels are the lowest. C High tide occurs one time per lunar cycle. D The light intensity of the moon varies within the lunar cycle.
A
A team of biologists develop a new drug, and one team member hypothesizes that the drug is incapable of freely passing across the plasma membrane and requires the help of membrane proteins to enter cells. Alternatively, another biologist on the team hypothesizes that the drug can diffuse passively across the plasma membrane like O2 and CO2 can. Which of the following, if true about the drug, best supports the alternative hypothesis that the new drug will exhibit simple diffusion across plasma membranes? The drug is a small nonpolar molecule. B The drug is a small charged molecule. C The drug is a large polar molecule. D The drug is a large charged molecule.
A
All of the following are density-dependent factors that limit animal populations EXCEPT A weather B predation C birthrate D food competition E mortality
A
Female European corn borer moths (Ostrinia nubilalis) produce the sex pheromone 11−tetradecenyl acetate (11−TDA), which attracts males of their species. 11−TDA can be produced in two forms, E and Z, each with a different three-dimensional shape. Researchers have discovered two different strains of the European corn borer moth living in the same area. Females of the E strain produce primarily the E form of 11−TDA and females of the Z strain produce primarily the Z form of 11−TDA. Males of both strains are more attracted to the form of 11−TDA produced by the females of the same strain. Which of the following best predicts a long-term effect of the differences between the E and Z strains? A The difference between the forms of the sex pheromone 11−TDA11−TDA produced by EE and ZZ strains will act as a prezygotic reproductive barrier leading to sympatric speciation. B The difference between the forms of the sex pheromone 11−TDA11−TDA produced by EE and ZZ strains will act as a postzygotic reproductive barrier, leading to allopatric speciation. C Since the EE and ZZ strains are both part of the same species, they will produce fertile offspring, leading to a single strain that produces both forms of 11−TDA11−TDA. D Since the EE and ZZ strains are found in the same geographic area, they will hybridize, leading to a single strain that produces the dominant form of 11−TDA11−TDA.
A
In 1996, the native Culex cedecei mosquitoes in southern Florida preferentially took blood meals from white-tailed deer and raccoons. It was predicted that changes in host population size would alter these host preferences. Additionally, it is known that cotton rats are often infected by the Everglades virus, which normally exists in animals, but is capable of infecting humans. Ecologists predict that increased feeding on cotton rats by C. cedecei may significantly increase the tendency of this virus to infect humans. Based on the data, which of the following most accurately matches a potential change with its predicted effects on the southern Florida ecosystem? A Introduction of a new top predator species that preys solely on Burmese pythons would cause an increase in the raccoon population. B If the population of Burmese pythons were to decrease, then the cotton rat population would increase. C If more Burmese pythons are introduced in the Everglades, then mosquitoes will begin feeding on white-tailed deer frequently again. D Introduction of a new snake species that competes with the Burmese python for food would lead to an increase in the white-tailed deer population. Answer A Correct. If the Burmese python population were reduced, then there would be less predation on raccoons, and the raccoon population would be able to grow larger. The same would be true of the white-tailed deer population.
A
In a simple ecosystem, a census of the populations in four successive trophic levels was taken as shown above. If level 1 is composed of photosynthetic autotrophs, then the trophic level with 780 individuals will most likely represent A primary consumers B secondary consumers C tertiary consumers D decomposers
A
Muscle cells have high ATP demands. Which of the following is a scientific claim about how the structure of the mitochondria in muscle cells should be different than it is in other cells because of the high energy demands of mitochondria? A The inner membrane of the mitochondria in muscle cells should have more folds to increase the surface area, allowing more ATPATP to be synthesized. B The inner membrane of the mitochondria in muscle cells should be more permeable to large enzymes, allowing the same reactions to occur in both compartments of the mitochondria. C The outer membrane of the mitochondria in muscle cells should be thicker, allowing more rapid diffusion of molecules into the mitochondria. D The outer membrane of the mitochondria of muscle cells should have more folds, increasing the surface area for faster diffusion of molecules from the cytoplasm.
A
Oxygen consumption can be used as a measure of metabolic rate because oxygen is A necessary for ATP synthesis by oxidative phosphorylation B necessary to replenish glycogen levels C necessary for fermentation to take place D required by all living organisms E required to break down the ethanol that is produced in muscles
A
Prairie dogs are small mammals that live in large colonies in burrows in the ground. Prairie dogs that are near their own relatives when a predator approaches are much more likely to issue a warning bark than those that are near unrelated prairie dogs. The prairie dogs that hear a warning bark are more likely to hide in their burrows than to remain above ground. However, the prairie dog that gives the warning bark is putting itself at increased risk of being identified and killed by the predator. Which of the following presents the most likely evolutionary explanation for the behaviors described? A The warning bark changes the behavior of the related prairie dogs nearby, allowing the prairie dog's family to have increased survival and reproductive success. B The barking prairie dog chooses to warn other prairie dogs, leading to more prairie dogs living above ground. C The barking prairie dog is alerting unrelated prairie dogs to the predator, so it is not giving any advantage to its own relatives. D The failure of the individual to bark when surrounded by unrelated prairie dogs ensures survival of the individual.
A
Some scientists claim that amphibians are currently experiencing a period of mass extinction. Which of the following should be included in an alternative hypothesis that would best support this claim? A The current extinction rate of amphibians compared with the background rate of extinction as determined by the fossil record B The extinction rate of amphibians in the 21st21st century compared with the extinction rate of amphibians during the 20th20th century C The number of species of amphibians currently alive compared with the number of amphibian species known to be extinct D The number of new amphibian species being discovered per year compared with the number of amphibian species becoming extinct during the same time period
A
The California grunion (Leuresthes tenuis) is a small marine fish that lives in shallow waters near the ocean shore. Grunions swim as far onto the beach as possible to mate and lay their eggs (spawn). A researcher proposes that the spawning behavior takes place when the nighttime tides are highest during the month. Which of the following pieces of evidence would best support the researcher's claim? A Grunion spawning occurs every two weeks during the spawning season. B Grunion spawning occurs when nighttime illumination levels are the lowest. C High tide occurs one time per lunar cycle. D The light intensity of the moon varies within the lunar cycle.
A
The diagram above shows the progression of ecological events after a fire in a particular ecosystem. Based on the diagram, which of the following best explains why the oak trees are later replaced by other trees? A Eventually the other trees grow taller than the oak trees and form a dense canopy that shades the understory. B Oak trees alter the pH of the soil, making the forest better suited for shrubs and other trees. C Roots of shrubs proliferate in the soil of the forest and prevent the oak trees from obtaining water. D Oak trees succumb to environmental pollutants more readily than do either the shrubs or the other trees.
A
The food web represented above does not include bacteria and fungi. Which of the following best describes a consequence of having no bacteria and fungi in the food web? A Grasses will have no direct access to chemical components recycled from dead organisms. B Rabbits will have no direct access to energy absorbed from secondary consumers. C Shrews will have no direct access to matter transferred from tertiary consumers. D Hawks will have no direct access to nitrogen acquired from the atmosphere.
A
The fossils in a layer of rock are significantly different from those in the rock layer directly above it. One hypothesis to explain the difference is that a major extinction event occurred at the point in time represented by the transition between the two rock layers. Which of the following is the best plan for collecting data to use in a test of the hypothesis? A Examining the upper part of the lower rock layer for evidence of a catastrophic event, such as the presence of shocked quartz, iridium, or soot particles B Digging farther into the hillside to look for a section of sedimentary rock that has a third layer below the two layers that were already identified C Comparing the genomes of organisms from different evolutionary lineages to estimate the relative geologic age of the upper rock layer D Searching fossil collections in several museums for examples of the types of features once shared among organisms that are now extinct
A
The placement and development of two bones of the reptilian jaw are very similar to that of two bones of the mammalian middle ear, which probably evolved from the reptile bones. The similarity of these bones is an example of A structural homology B speciation C vestigial structures D convergent evolution E adaptive radiation
A
The reactions of glycolysis occur in the A cytosol B nucleus C matrix of the mitochondrion D membranes of the mitochondrion E stroma of the chloroplast
A
Two nutrient solutions are maintained at the same pH. Actively respiring mitochondria are isolated and placed into each of the two solutions. Oxygen gas is bubbled into one solution. The other solution is depleted of available oxygen. Which of the following best explains why ATP production is greater in the tube with oxygen than in the tube without oxygen? A The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen. B Electron transport is reduced in the absence of a plasma membrane. C In the absence of oxygen, oxidative phosphorylation produces more ATP than does fermentation. D In the presence of oxygen, glycolysis produces more ATP than in the absence of oxygen.
A
Which of the following best describes opportunistic, or r-strategy, organisms? A They reach sexual maturity rapidly. B They reach their adult size slowly. C They attain a large body size. D They live for a long time. E The size of their population remains fairly constant.
A
Wolves, a top predator, were reintroduced to Yellowstone National Park in 1995 after a 50-year absence. In a multiyear study, the numbers of wolves and elk were monitored. The data are shown in Figure 1. In two different environments scientists monitored the percent of aspen trees browsed by herbivores (Figure 2) as well as the growth of the trees (Figure 3). The upland environments consist mostly of flat forested areas. The riparian environments are areas along streams with steep, wooded banks. Based on the data, which of the following behaviors in elk could account for the differences between the percent of aspens browsed by herbivores and the height of aspen trees in riparian and upland environments? A Elk tend to avoid riparian areas where the steep, wooded riverbanks make it difficult to escape predators. B Elk tend to prefer riparian areas where there is easy access to water. C Elk tend to avoid upland areas where trees are too tall to be easily eaten. D Elk tend to prefer upland areas where there are richer sources of mineral nutrients, such as potassium and iodine.
A
n the year 2000, specimens of Caulerpa taxifolia,a green alga used in tropical aquariums, were found off the coast of California. Native to the Indian Ocean, C. taxifolia is known for aggressive growth and an ability to compete with sea grasses.It is currently on an international list of invasive species. Which of the following best predicts the consequences of the introduction of C. taxifolia to the California coast? A Without natural herbivores or competitors,C. taxifolia will grow rapidly and crowd out native species of producers. B C. taxifolia will have a hard time establishing itself because it will have to compete against native species of sea grasses, which are better adapted to the environment. C C. taxifolia will grow rapidly, leading to an increase in the diversity of producers. D Because it is not in the Indian Ocean, its natural environment, C. taxifolia will not be able to grow efficiently.
A
A fish population of 250 in a pond has a maximum annual rate of increase of 0.8. If the carrying capacity of the pond is 1,500 for this species, what is the expected population size after one year? A 167 B 417 C 450 D 500
Answer B Correct. Using the formula for logistic growth, dNdt=rmaxN(K−NK)dNdt=rmaxN(K−NK) , the increase in population is calculated: 8×250(1,500−2501,500)=166.78×250(1,500−2501,500)=166.7. Adding 166.7 to 250 (the current population) provides a predicted population of 417 after one year.
A population of 250 birds inhabit the canopy of a tropical rain forest that has a carrying capacity of 400 birds. What is the maximum population growth rate (rmax) if the population grows to 283 in one year? A 0.12 B 0.13 C 0.35 D 0.39
Answer C Correct. This calculation uses the correct population size of N=250N=250 and includes consideration of the carrying capacity (K=400)(K=400) as part of the logistical growth pattern, as described by dNdt=(283−250)=rmaxN(K−NK)dNdt=(283−250)=rmaxN(K−NK) : 33=rmax×250×(400−250400)33=rmax×250×(400−250400) and rmax=0.35rmax=0.35.
A colony of termites was exposed to an atmosphere of 100 percent oxygen for three days. The insects were not immediately harmed by the treatment, but the protozoa that lived in the termites' guts were eliminated. The treated termites continued to behave normally and to eat wood, but they began to starve after a short time. When the treated termites were instead fed wood contaminated with the feces of untreated termites, the treated termites regained the ability to digest wood and no longer starved. The best analysis of the results of the experiment is that A infection with protozoa causes the termites to switch to fermentation B cooperative interactions between the termites and the protozoa allow termites to extract energy from wood to survive C the termite immune system eliminates protozoa from the gut D termites digest protozoa as their main source of energy
B
A researcher claims that the synthesis of ATP from ADP and inorganic phosphate (Pi) is essential to cellular function. Which of the following statements best helps justify the researcher's claim? A ADPADP is a small molecule that some cells release into their environment as a way of communicating with other cells. B ATPATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy. C Inorganic phosphate (Pi)(Pi) is a substance that cells typically acquire from their environment. D ATPATP synthase is a mitochondrial enzyme that catalyzes the conversion of ADPADP and PiPi to ATPATP.
B
All of the following statements about the pyramid of biomass are correct EXCEPT: A Biomass is the total dry mass of the organisms present. B The base of the pyramid generally represents primary consumers. C The amount of biomass at a particular level of the pyramid depends on the amount of energy available. D Certain toxins tend to become concentrated at upper levels of the pyramid. E Biomass pyramids tend to vary for different ecosystems.
B
Beaked whales feed at various depths, but they defecate at the ocean's surface. Nitrogen-rich whale feces deposited in surface waters supply nutrients for algae that are eaten by surface dwelling fish. Which of the following best predicts what would happen if the whale population decreased? A There would be a reduction in surface nitrogen concentration, which would cause an algal bloom. B The surface fish populations would decline due to reduced populations of algae. C The remaining whales would accumulate mutations at a faster rate. D The remaining whales would be forced to forage in the deepest parts of the ocean.
B
DNADNA and RNARNA are nucleic acids that can store biological information based on the sequence of their nucleotide monomers. Figure 1 shows a short segment of each of the two types of nucleic acids. Which of the following best describes a structural difference between DNADNA and RNARNA? A DNADNA contains four types of nitrogenous bases, whereas RNARNA contains only two types of nitrogenous bases. B The backbone of DNADNA contains deoxyribose, whereas the backbone of RNARNA contains ribose. C A DNADNA molecule is composed of two parallel strands with the same 5′5′ to 3′3′ directionality, whereas an RNARNA molecule is composed of only one 5′5′ to 3′3′ strand. D Phosphate groups provide rigidity to DNADNA, but RNARNA is flexible and contains no phosphate groups.
B
Developers have approved a project that will permanently reduce the primary producers' biomass by 50 percent and remove all rabbits and deer. Which of the following is the most likely result at the completion of the project? A The biomass of coyotes will be 6 kg, and the biomass of hawks will be 0.5 kg. B The biomass of coyotes will be dramatically reduced. C The coyotes will switch prey preferences and outcompete the hawks. D There will be 50 percent fewer voles and 90 percent fewer hawks.
B
Dr. Robert Hazen has worked to develop a hypothesis that explains the origin of life on Earth. His work has focused on hydrothermal vents, which are cracks in the ocean floor. Water heated by molten rock beneath the crust escapes from these vents at very high temperatures, producing hot, high‑pressure environments at the vents on the ocean floor. In order to provide evidence that these vents may be areas where life originated, which of the following states a null hypothesis Hazen might have used to begin his research? A Organic molecules were transported to the hydrothermal vents via a meteorite, thereby seeding them with precursors for more complex molecules. B The temperatures and pressures found in hydrothermal vents resemble conditions described in currently accepted origins of life hypotheses. C Organic waste sinking to the ocean floor would have used the unique hot water environment as an energy source to begin manufacturing food. D Chemosynthetic organisms can best develop in the hydrothermal environment, manufacturing nutrients for other living things to feed on.
B
During respiration, most ATP is formed as a direct result of the net movement of A potassium against a concentration gradient B protons down a concentration gradient C electrons against a concentration gradient D electrons through a channel E sodium ions into the cell
B
Experimental evidence shows that the process of glycolysis is present and virtually identical in organisms from all three domains, Archaea, Bacteria, and Eukarya. Which of the following hypotheses could be best supported by this evidence? A All organisms carry out glycolysis in mitochondria. B Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life. C Across the three domains, all organisms depend solely on the process of anaerobic respiration for ATP production. D The presence of glycolysis as an energy-releasing process in all organisms suggests that convergent evolution occurred.
B
Figure 1. Nucleic acid fragment Which of the following characteristics of Figure 1 best shows that the fragment is RNARNA and not DNADNA? A The 5′5′ to 3′3′ orientation of the nucleotide chain B The identity of each nitrogenous base C The charges on the phosphate groups D The type of bond linking the nucleotides together
B
In an investigation, the relationship between black bears, salmon, and influx of marine nitrogen into the area around a southwestern Alaskan stream was studied. The investigators established several test plots of the same size along the stream with the following species composition: no salmon or black bears (N), bears but not salmon (B), salmon but not bears (S), and a plot where salmon and bears interact (SB). Nitrogen influx in the different sampling areas was measured as a means of assessing the impact of the different species on the health of the ecosystem. The data are plotted in Figure 1. If a dam is built downstream and prevents salmon migration to the test sites, which of the following most accurately predicts the impact on nitrogen influx? A Nitrogen influx will increase because the bears will no longer store nitrogen from the salmon. B Nitrogen influx will decrease because there will be less bear-salmon interaction. C Nitrogen influx will remain stable because organisms other than bears and salmon will mobilize nitrogen in the environment. D Nitrogen influx will increase because bears will no longer lose nitrogen to the salmon.
B
In the "RNA world" model for the origin of life, the first protocells (probionts) relied on RNA, not DNA, for information storage and transmission. Which of the following could best be considered evidence in support of the RNA world model? A DNA is more stable than is RNA. B Some RNA molecules in contemporary cells have catalytic function. C RNA is so complex in both structure and function that it must have preceded DNA. D RNA has secondary structure whereas DNA does not.
B
In the experiment, the researchers determined the relative abundance of two bacterial species found in the rumen of cattle. The rumen is a part of the stomach that acts as a fermentation chamber in cattle and other ruminants. Shown in the table are the results from before and after an abrupt change in the cattle's diet. Based on the results, which of the following best explains why the initial hypothesis should be revised? A The diets were too similar, since cellulose and starch are both carbohydrates obtained from eating plants. B The abundance of one of the bacterial species increased in response to the change in diet. C The change in the diversity of microorganisms had no observable effect on cattle physiology. D The ability of rumen fluid to resist changes in pH counteracted the changes in microorganism diversity.
B
On a large volcanic island, researchers are studying a population of annual herbaceous plants. Which of the following observations best supports the prediction that speciation will occur within the existing plant population? A Individuals of the species sometimes reproduce asexually by producing runners. B Lava has separated the population into two areas: an upland forest and a lowland marsh. C Multiple groups of birds depend on the fruit produced by the plants as a source of food. D The plants produce more seeds during warm summers than they do during cool summers.
B
Plant cell walls are composed of cellulose, while fungal cell walls are composed of chitin. A group of scientists hypothesize that this difference means the cell wall has largely different functions in plant cells and fungal cells. Alternatively, another group of scientists hypothesize that despite their biochemical differences, plant and fungal cell walls serve similar functions. Which of the following observations would best support the alternative hypothesis described above? A Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. B In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane. C Some plant cells have secondary cell walls that confer additional rigidity, while fungal cells do not. D Photosynthesis occurs in plant cells, but it does not occur in fungal cells.
B
Rhagoletis pomonella is a parasitic fly native to North America that infests fruit trees. The female fly lays her eggs in the fruit. The larvae hatch and burrow through the developing fruit. The next year, the adult flies emerge. Prior to the European colonization of North America, the major host of Rhagoletis was a native species of hawthorn, Crataegus marshallii. The domestic apple tree, Malus domestica, is not native to North America, but was imported by European settlers in the late 1700s and early 1800s. When apple trees were first imported into North America, there was no evidence that Rhagoletis could use them as hosts. Apples set fruit earlier in the season and develop faster, where hawthorns set later and develop more slowly. Recent analysis of Rhagoletis populations has shown that two distinct populations of flies have evolved from the original ancestral population of flies that were parasitic on hawthorns. One population infests only apple trees, and the other infests only hawthorns. The life cycles of both fly populations are coordinated with those of their host trees. The flies of each population apparently can distinguish and select mates with similar host preferences and reject mates from the population specific to the other host tree. There is very little hybridization (only about 5 percent) between the two groups. Initially, which of the following isolating mechanisms is likely to have been the most important in preventing gene flow between the two populations of Rhagoletis? A Gamete incompatibility B Temporal isolation C Mechanical isolation D Reduced hybrid viability
B
Testosterone oxido-reductase is a liver enzyme that regulates testosterone levels in alligators. One study compared testosterone oxido-reductase activity between male and female alligators from Lake Woodruff, a relatively pristine environment, and from Lake Apopka, an area that has suffered severe contamination. The graph above depicts the findings of that study. The data in the graph best support which of the following claims? A Environmental contamination elevates total testosterone oxido-reductase activity in females. B Environmental contamination reduces total testosterone oxido-reductase activity in females. C Environmental contamination elevates total testosterone oxido-reductase activity in males. D Environmental contamination reduces total testosterone oxido-reductase activity in males.
B
The appearance of a fertile, polyploid individual within a population of diploid organisms is a possible source of a new species. If this individual is capable of reproducing to form a new population, scientists would consider this to be an example of A allopatric speciation B sympatric speciation C polygenic inheritance D genetic drift E Hardy-Weinberg equilibrium
B
The deep ocean floor communities contain very little life. In constant darkness, the water at these depths hovers around 2°C. Sparsely distributed in this environment are hydrothermal vent ecosystems. Superheated water streams out of the vents at temperatures approaching 400°C. These waters are rich in inorganic materials, including carbon dioxide and hydrogen sulfide. Hydrothermal vent zones have a density of organisms 10,000 to 100,000 times greater than found on the surrounding seafloor. Scientists have studied these vents to determine the energy source for these communities and the identity of the primary producers in the perpetual darkness of the ocean floor. As expected, they found a total absence of photosynthetic organisms at all vents, identifying mats of bacteria as the producers of the carbon compounds that are used by the rest of the community for growth, repair, and as an energy source. Which of the following describes how the vent bacteria harvest energy to produce organic compounds for use by the vent community? A The bacteria use the heat from the hot water to assemble carbon-based materials from inorganic molecules. B The bacteria function as chemoautotrophs, extracting energy from hydrogen-rich inorganic molecules. C Organic matter drifting down from the ocean's surface is used to make molecules with enough energy to sustain the vent community. D The bacteria can recycle the energy from the waste products and dead material produced by the heterotrophs of the vent community into energy-rich carbon compounds that can be recycled.
B
The wing of a bat, the flipper of a whale, and the forelimb of a horse appear very different, yet detailed studies reveal the presence of the same basic bone pattern. These structures are examples of A analogous structures B homologous structures C vestigial structures D balanced polymorphism E convergent 'evolution
B
Which metabolic process is common to both aerobic cellular respiration and alcoholic fermentation? A Krebs cycle B Glycolysis C Electron transport chain D Conversion of pyruvic acid to acetyl CoA E Production of a proton gradient
B
Which of the following best describes how amino acids affect the tertiary structure of a protein? A The number of amino acids determines the tertiary structure of the protein. B The interactions of the different RR-groups with other RR-groups and with their environment determine the tertiary structure of the protein. C The RR-group of the last amino acid that is added to a growing polypeptide chain determines the next amino acid that is added to the chain. D The sequence of the amino acids in the polypeptide chain determines the protein's primary structure but has no effect on its tertiary structure.
B
Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins? A The change has no effect on the stability of the protein because only one type of amino acid is involved. B The change leads to increased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins. C The change leads to decreased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins. D The change leads to increased protein stability only when the added cysteine amino acids are next to other cysteine amino acids in the primary structure.
B
Which of the following best describes the structures of carbohydrates? A They only occur as disaccharides. B They occur as monomers, chains of monomers, and branched structures. C They only occur as long and branched structures. D They occur as chains of monomers that hydrogen bond with complementary chains of monomers.
B
Which of the following claims is scientifically accurate and consistent with an observation that a decrease in lysosome production within a cell leads to a decline in mitochondrial activity? A lack of lysosomes will cause a decrease in the synthesis of enzymes necessary for cellular respiration. B Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration. C Fewer lysosomes will be available to store materials required for the functioning of the mitochondria. D Lysosomes will not be available to modify proteins so that they are targeted to the mitochondria.
B
Which of the following graphs is the most appropriate representation of the experimental results documented in the table? A Pie graph B Bar graph C Line Graph D Dot graph
B
Which of the following most accurately explains an impact of Burmese pythons on the Everglades community in southern Florida using the data provided? A Python parasitism has reduced the population of white-tailed deer and raccoons. B Python predation has caused a trophic cascade that changed the mosquitoes' niche. C Pythons have a mutual symbiosis with cotton rats, allowing their population to increase. D Intraspecific competition for food between white-tailed deer and raccoons has increased due to pythons.
B
Which of the following questions will best direct an investigation of the mechanism of ATP synthase? A What is the source of the inorganic phosphate that is used to generate ATP from ADP? B Is the phosphorylation of ADP by ATP synthase dependent on the formation of a proton gradient? C Can ATP synthase use the energy released by phosphorylation of ADP to pump protons against a concentration gradient? D Can oxidative phosphorylation be uncoupled from the electron transport chain?
B
Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules? A Rabbits eat plants and use energy absorbed from the plants to make carbon atoms from electrons, protons, and neutrons in the air. B Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules. C Rabbits eat plants and use water absorbed from the plants to hydrolyze CO2CO2, which the rabbits breathe in from the air and use as a carbon source. D Rabbits eat plants and make carbon-containing molecules by using carbon atoms that the plants absorbed from the soil and stored in the cells of their leaves.
B
Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules? Rabbits eat plants and use energy absorbed from the plants to make carbon atoms from electrons, protons, and neutrons in the air. B Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules. C Rabbits eat plants and use water absorbed from the plants to hydrolyze CO2CO2, which the rabbits breathe in from the air and use as a carbon source. D Rabbits eat plants and make carbon-containing molecules by using carbon atoms that the plants absorbed from the soil and stored in the cells of their leaves.
B
Which of the following statements best justifies the use of the experimental results in an investigation of interspecies competition? A When two populations use different sources of energy, one of the populations will thrive in a shared environment and the other will become extinct. B When two populations use the same sources of energy, resource availability in a shared environment limits the growth of both populations. C Because the change in entropy of a system containing two different species is always positive, populations typically grow faster in shared environments. D Because the free energy of a system containing two different species is always negative, populations that utilize similar resources cannot coexist in nature.
B
Which of the following statements correctly describes a typical trend during the initial stages of succession in a terrestrial ecosystem? A Food webs become less complex. B Diversity of plant species increases. C The amount of biomass and nonliving organicmatter decreases. D The litter layer becomes thinner because ofincreased assimilation of nutrients by shrubsand trees. E The storage of inorganic nutrients within individual plants decreases.
B
Which statement best helps explain the formation of the hydrogen bond represented in the figure? A The oxygen has a partial positive charge, and the nitrogen has a partial negative charge. B The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge. C The hydrogen attached to the oxygen has a partial negative charge, and the nitrogen also has a partial negative charge. D The nitrogen has a partial positive charge, and the hydrogen attached to the oxygen also has a partial positive charge.
B
Which statement best helps explain the formation of the hydrogen bond represented in the figure? The oxygen has a partial positive charge, and the nitrogen has a partial negative charge. B The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge. C The hydrogen attached to the oxygen has a partial negative charge, and the nitrogen also has a partial negative charge. D The nitrogen has a partial positive charge, and the hydrogen attached to the oxygen also has a partial positive charge.
B
(A) Cytochrome(B) FADH2(C) NAD+(D) NADP+(E) Oxygen (O2) An intermediate electron acceptor for oxidations that occur in both glycolysis and in Krebs cycle reactions A Cytochrome B FADH2 C NAD+ D NADP+ E Oxygen (O2)
C
A feature of organic compounds NOT found in inorganic compounds is the presence of A ionizing chemical groups B electrons C carbon atoms covalently bonded to each other D oxygen E hydrogen bonds
C
A group of students designed an experiment to determine the effect of compost on the germination and growth of plants. The students set up experimental plots by mixing different ratios of soil and compost. They planted 20 pea and 20 melon seeds in each plot and watered each plot regularly. The students recorded the number of seeds that germinated, and as the plants grew, they recorded plant length, number and size of leaves, and general health observations. The following observations were recorded. In all treatments, more pea seeds germinated than melon seeds. There was a week of rainy weather at three weeks. Melon plants developed a fungal growth at four weeks. Melon plants grew longer than pea plants, but many melon leaves showed signs of yellowing as the weeks passed. The students concluded that pea plants grew better in compost than did melon plants. Which of the following best addresses the validity of the conclusion made by the students? A The conclusion is valid because the independent and dependent variables in the experiment were controlled. B The conclusion is valid because the experimental design included a large sample size. C The conclusion is invalid because other variables in the experiment (both biotic and abiotic) affected the results. D The conclusion is invalid because the units of measurement were not given in the experimental design.
C
According to the data, the crickets at 25o C have greater oxygen consumption per gram of tissue than do the crickets at 10o C. This trend in oxygen consumption is the opposite of that in the mice. The difference in trends in oxygen consumption among crickets and mice is due to their A relative size B mode of nutrition C mode of internal temperature regulation D mode of ATP production
C
All of the following are examples of prezygotic genetic isolating mechanisms EXCEPT: A Male fireflies of different species have differing flash patterns. B Three closely related orchid species flower on different days. C The progeny of a cross between two different lizard species fail to develop properly. D One species of snake lives in water and another is terrestrial. E Peeper frogs mate in April, and tree frogs mate in June.
C
Bacteriophages are viruses that infect bacteria. In an experiment, bacteriophages were labeled with either radioactive phosphorus or radioactive sulfur. The labeled bacteriophages were incubated with bacteria for a brief amount of time and then removed. The infected bacteria cells were found to contain significant amounts of radioactive phosphorus but not radioactive sulfur. Based on the results of the experiment, which of the following types of molecules did the bacteriophages most likely inject into the bacteria cells? A Simple carbohydrate B Amino acid C DNA D Polypeptide
C
Based on the experimental results, which of the following statements best describes the relationship of the two populations that were studied in the investigation? A The populations have a parasitic relationship in which one species requires the presence of the other to reproduce. B The populations have a symbiotic relationship in which both species require the presence of the other to reproduce. C The populations have a competitive relationship in which each species limits the ability of the other to reproduce. D The populations have a predator/prey relationship in which one species positively influences the ability of the other to reproduce.
C
Based on the molecular structures shown in the figure, which molecule is likely to be solid at room temperature? A Linoleic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together. B Linoleic acid, because the presence of carbon-carbon double bonds prevents the molecules from packing closely together. C Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together. D Palmitic acid, because the presence of carbon-carbon double bonds prevents the molecules from packing closely together.
C
By discharging electric sparks into a laboratory chamber atmosphere that consisted of water vapor, hydrogen gas, methane, and ammonia, Stanley Miller obtained data that showed that a number of organic molecules, including many amino acids, could be synthesized. Miller was attempting to model early Earth conditions as understood in the 1950s. The results of Miller's experiments best support which of the following hypotheses? A The molecules essential to life today did not exist at the time Earth was first formed. B The molecules essential to life today could not have been carried to the primordial Earth by a comet or meteorite. C The molecules essential to life today could have formed under early Earth conditions. D The molecules essential to life today were initially self-replicating proteins that were synthesized approximately four billion years ago.
C
Commercial bananas are grown as a monoculture, with all banana plants cloned from one original banana plant. The commercial strains of bananas are seedless, so each new banana plant has to be manually planted from a cutting of an existing banana root. In the 1950s, the Gros Michel banana strain, the dominant export banana at that time, was destroyed by the fungus Fusarium oxysporum. A new Fusarium resistant variety, the Cavendish banana, was developed and is currently the banana strain grown for export. Recently, a Fusarium strain that successfully attacks the Cavendish strain has been documented. Which of the following best provides reasoning supporting a method that would help protect commercial banana crops from infection by pathogenic organisms such as Fusarium fungi? A The commercial banana strains should be exposed to XX-rays to encourage random mutations that will then be passed to offspring, producing resistance to pathogenic organisms. B The Cavendish banana plants should be exposed to pathogenic organisms under controlled conditions, so the plants can be encouraged to mutate and develop resistance to the pathogens. C The commercial banana strains should not be grown in monocultures, since many pathogenic organisms are able to evolve rapidly in response to a single selective pressure. D Growing the Cavendish strain under different conditions will allow natural selection to produce the variation needed to resist infection by pathogenic organisms.
C
Figure 1. A model of the intracellular transport of a newly synthesized secreted protein Based on the model, the newly synthesized protein is transported directly from the endoplasmic reticulum to which of the following? The nucleus B The plasma membrane C The Golgi complex D The extracellular space
C
In 1996, the native Culex cedecei mosquitoes in southern Florida preferentially took blood meals from white-tailed deer and raccoons. It was predicted that changes in host population size would alter these host preferences. Additionally, it is known that cotton rats are often infected by the Everglades virus, which normally exists in animals, but is capable of infecting humans. Ecologists predict that increased feeding on cotton rats by C. cedecei may significantly increase the tendency of this virus to infect humans. Which of the following populations have significantly decreased in size between 1996 and 2011 ? A White-tailed deer only B Cotton rats and rabbits only C White-tailed deer and raccoons only D White-tailed deer, raccoons, and cotton rats
C
In an experiment, a scientist isolates mitochondria from living cells and suspends them in two different buffered solutions. One solution is maintained at pH 4, while the other solution is maintained at pH 9. The scientist finds that mitochondria in the solution at pH 4 continue to produce ATP but those in the pH 9 solution do not. The results of the experiment can be used as evidence in support of which of the following scientific claims about mitochondrial activity? A Mitochondria in a cell-free environment are unable to convert thermal energy into ATP. B The electron transport chain pumps electrons from the cytosol to the mitochondrial matrix. C ATP production in mitochondria requires a hydrogen ion gradient that favors movement of protons into the mitochondrial matrix. D ATP synthase molecules change their orientation in relation to the proton gradient across the mitochondrial membrane.
C
In the Arctic Ocean, the predominant primary producers are phytoplankton. Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In years when there is more open water (less ice coverage), there are more zooplankton and fish than in years with less open water (more ice coverage). Based on the graph above, the difference is most likely because A when there is less open water, light is blocked from the zooplankton, so they cannot produce as much food for the fish B when there is more open water, the temperature is warmer, so the zooplankton and fish populations increase in size C the ice blocks the light, so in years with more ice coverage, there is less photosynthesis by the phytoplankton D the ice increases the light available for photosynthesis, so primary production increases and zooplankton populations increase in size
C
In the process of succession, which of the following is true of K-selected plant species? A They keep their carrying capacity at minimum level B They usually reproduce early in life. C They are usually found in climax stages of succession. D They are the dominant species in early stages of succession. E They have a short lifespan.
C
Lobe-finned fishes were present in the oceans of the world approximately 400 million years ago. The first tetrapods (vertebrates that had limbs and could move on land) date to about 365 million years ago. One hypothesis states that early tetrapods evolved from lobe-finned fishes. Which of the following is the best plan for testing the hypothesis? A Determining the number of fins found on lobe-finned fishes from different geographical locations B Measuring the proportion of radioisotopes found in fossils of early tetrapods C Comparing the arrangements of bones in the fins of lobe-finned fishes and limbs of the earliest tetrapods D Sequencing DNA isolated from fossils of lobe-finned fishes to determine the size of the genome
C
Members of which species are most likely to be omnivorous? A A B B C C D D E E
C
One model of a sustainable fisheries practice is for individual fish to be removed from a natural population at a rate equal to the highest possible growth rate of an ideal population. The graph above represents a population of bluefin tuna living along the Atlantic coast. At which labeled point in the graph is the population growth rate the highest? A I B II C III D IV
C
One of the oldest known mammalian fossils belongs to a small furry species, Hadrocodium wui, that lived 195 million years ago. For the following 100 million years, only a small number of groups of mammalian fossils are found in the fossil record. By 65 million years ago, the nonavian dinosaurs were extinct. By 55 million years ago, there were 130 mammal genera, including 4,000 different species that occupied a wide variety of habitats. Which of the following best describes the cause of the rapid increase in the number of mammalian species between 65 and 55 million years ago? A It took over 100 million years for enough random mutations to occur in the genomes of early mammals to provide the variation needed for the observed speciation. B It took over 100 million years for the early mammals to disperse over a wide enough geographic area to allow allopatric speciation to occur. C After the dinosaur extinction, many ecological niches became available, leading to the adaptive radiation of mammals. D After the dinosaur extinction, mammal population sizes increased, allowing species to become more easily detectable in the fossil record.
C
Rock pocket mice live in the deserts of the American southwest. Ancestral pocket mice all had light-colored coats that blended in with the region's rocks and sandy soil, keeping the mice hidden from predatory owls. About 1.7 million years ago, a series of volcanic eruptions spewed out wide trails of black lava into the middle of rock pocket mouse territory. Currently there are two color morphs of rock pocket mice: light-colored mice that are typically found in habitats with sandy soil, and dark-colored mice that are typically found in habitats with dark-colored lava rocks. Which of the following best justifies the claim that alleles that may be adaptive in one type of environment can be deleterious in another because of different selective pressures? A Light- and dark-colored mice survive in many environments because they are able to avoid predation by moving into tunnels. B Light-colored mice are more likely to survive than dark-colored mice in habitats with lava rocks and sandy soil. C Light-colored mice are significantly more susceptible to predation by owls in habitats with lava rocks than in habitats with sandy soil. D Dark-colored mice are more likely to survive than light-colored mice in habitats with lava rocks and sandy soil.
C
The population density at point Q indicates that A exponential population growth is occurring B predation is beginning to occur C the reproductive rate equals the death rate D the average age of individuals is decreasing E the reproductive capacity for each individual is increasing
C
This group of questions refers to the following groups of biological compounds. (A) Proteins(B) Carbohydrates(C) Nucleic acids(D) Lipids(E) Steroids Used to carry the genetic code A Proteins B Carbohydrates C Nucleic acids D Lipids E Steroids
C
Two populations of a species of squirrel are geographically isolated from each other. Although they have the same population density, one population is significantly larger in number than the other. A new bacterial disease, which is easily spread and extremely virulent, affects both populations at the same time. Which of the following is the best prediction of how the new disease will affect the two populations? A The two populations will be equally affected, because the ability to trigger an immune response is randomly distributed among all squirrels of that species. B The larger population will be less affected by the disease than will the smaller population, because the mutation rate of the larger population is higher than the mutation rate of the smaller population. C The smaller population will be more affected than will the larger population, because the smaller population has less genetic variation than the larger population has. D The smaller population will be less affected than will the larger population, because the smaller population exhibits more genetic drift than the larger population exhibits.
C
Which of the following best describes the formation of the bond shown in Figure 1 ? A An ionic bond is formed between a carbon atom of one amino acid and the nitrogen atom of the other amino acid. B An ionic bond is formed when the negative charge of an OHOH group is balanced by the positive charge of a hydrogen ion. C A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2OH2O . D A covalent bond is formed that replaces the hydrogen bond between the OHOH group and the HH atom.
C
Which of the following data would be most helpful in predicting possible disruptions to the relationship between the predator and its prey? A Time of day, because as days become shorter, nighttime hunting increases B Average birth weight of predators, because heavier offspring will begin hunting at younger ages C Numbers of additional predator species, because additional predators will increase competition for prey D Prey metabolic rates, because predators are less successful against prey with higher metabolic rates
C
Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells? A An increase in blood pH due to the accumulation of lactic acid B No ATP production due to the absence of substrate-level phosphorylation C A buildup of lactic acid in the muscle tissue due to fermentation D A decrease in the oxidation of fatty acids due to a shortage of ATP
C
Which of the following is an accurate interpretation of the data in Figure 1 ? A R. richardsoni is found significantly more frequently on Species 4 compared to Species 3. B R. colwelli is found significantly more frequently on Species 1 compared to Species 2. C R. richardsoni is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2. D R. colwelli is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2.
C
Which of the following is an example of a density-independent limitation on a population? A In larger population densities of rabbits, the percentage of rabbits infected with bacteria is greater. B At greater concentrations of bacteria, nutrient supplies diminish and population growth ceases. C At higher temperatures, more tomato plants in a population become infested with nematodes than at lower temperatures. D In denser stands of oak trees, greater percentages of trees are attacked by gypsy moths than in less dense stands. E Once the population of grouse exceeds a certain number, the predation rate becomes very high.
C
Which of the following is responsible for the cohesive property of water? A Hydrogen bonds between the oxygen atoms of two adjacent water molecules B Covalent bonds between the hydrogen atoms of two adjacent water molecules C Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule D Covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule E Hydrogen bonds between water molecules and other types of molecules
C
Which of the following statements about glucose, galactose, and fructose is most likely true? A The carbohydrates have the same properties because they have the same number of carbon, hydrogen, and oxygen atoms. B The carbohydrates have the same properties because they each have a single carbon-oxygen double bond. C The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms. D The carbohydrates have different properties because they have different numbers of carbon-carbon bonds.
C
Which of the following statements best predicts the effect of increased cottonwood growth on the food web? A Increased cottonwood growth will lead to an increase in the number of primary consumers, resulting in more competition between kestrels and sparrows for food. B Increased cottonwood growth will decrease the habitat available for lizards, resulting in a decline in the number of kestrels. C Increased cottonwood growth will provide more resources for cicadas, resulting in an increase in the kestrel population. D Increased cottonwood growth will lead to a large accumulation of dead wood that serves as fuel for wildfires, resulting in the collapse of the food web.
C
Which of the following statements best supports the claim that organisms share fundamental processes as a result of evolution? A All organisms that are introduced into new environments have the capacity to fill vacant ecological roles. B All organisms have the ability to utilize oxygen to harness energy from the chemical breakdown of organic compounds. C All organisms share a genetic code organized into triplet codons, making it possible for one organism to express a gene from another organism. D All organisms possess structures such as chloroplasts and mitochondria within their cells that reflect past symbiotic relationships between prokaryotic precursors.
C
Which species would most likely represent humans if they were part of this ecosystem? A A B B C C D D E E
C
What would the population size of sika deer be one year after the carrying capacity increased to 70,000 as a result of deforestation? Assume rmax does not change. A The population would grow to 70,000 deer in a year, because they would occupy the entire environmental niche. B The population would grow to 91,060 deer in a year, but then they would die off from a lack of resources. C The population would grow to 63,667 deer in a year, and the growth rate would decrease the following year. D The population would remain at 58,000 deer, since it had already stabilized.
Correct. dNdt=rmaxN(K−NK)dNdt=rmaxN(K−NK) should be used to calculate the increase in the population size after a year: 0.57×58,000×(70,000−58,00070,000)=5,6670.57×58,000×(70,000−58,00070,000)=5,667 . The new population size would be 5,667+58,000=63,6675,667+58,000=63,667 . The growth rate would decrease the following year because the population would be closer to the new carrying capacity and (K−NK)(K−NK) would get smaller.
A small number of lizards from a mainland population have been deposited on four isolated islands because of the effects of a rare strong storm. Which of the following best predicts the outcome of these lizards reproducing for many generations on the islands? A Courtship rituals specific to each island lizard species prevent the lizards from interbreeding. B Speciation results from bottleneck events that happened before the ancestral species reached the islands. C The different species that currently exist are the result of hybridization between lizards from different islands. D The isolation prevents gene flow; thus, the lizards on different islands experience prezygotic isolation.
D
According to the chemiosmotic theory (chemiosmotic coupling), the energy required to move protons from the mitochondrial matrix to the intermembrane space against a concentration gradient comes most directly from A photons of red or blue light B the hydrolysis of ATP C the breakdown of high-energy fatty acids inthe mitochondrial matrix D electrons flowing along the electron transportchain E substrate-level phosphorylation
D
Aquaporins are channel proteins that facilitate the transport of water across the cell membrane. One group of researchers hypothesizes that without functional aquaporins, no water will be able to enter the cell. A different group proposes an alternative hypothesis, stating that even with nonfunctional aquaporins, a small amount of water will still cross the cell membrane. An experiment is set up in which plant cells with mutated (nonfunctional) aquaporins and plant cells with normally functioning aquaporins are both placed in distilled water. Which of the following data would support the alternative hypothesis? Cells with functional aquaporins exhibit low turgor pressure and are hypertonic. B Cells with functional aquaporins exhibit high turgor pressure and are hypotonic. C Cells with mutated aquaporins exhibit an absence of turgor pressure and are completely plasmolyzed. D Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.
D
As depicted in the diagram, honeybees communicate the location of flower patches to members of their hives with waggle dances that give information about the direction and distance to the flowers. Which of the following statements about how honeybees communicate the position of flower patches is most consistent with the model? A The number of repetitions of the waggle dance indicates the quality of the pollen source. B The total area covered by any waggle dance leads bees to the target flowers. C The angle of the waggle phase relative to the vertical plane indicates the position of the target flowers relative to another beehive. D The farther the target flowers from the hive, the longer the waggle phase.
D
Assume there are 50,000 joules (J) of energy available in trophic level II in the figure. According to the conventional model of energy flow in ecosystems, which of the following statements correctly describes the flow of energy in the system? A Trophic level I generates a maximum of 50,000 J of energy. B Trophic level I has approximately 5,000 J of available energy. C Trophic level III has approximately 50 J of available energy. D Trophic level IV has approximately 500 J of available energy.
D
Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface? A Covalent bonds between water molecules and the air above provide cohesion, which causes tiny bubbles to form under the feet of the insect. B Ionic bonds between molecules at the surface of the water provide an electric charge, which attracts the feet of the insect, keeping it on the surface. C Polar covalent bonds between molecules at the surface of the water provide adhesion, which supports the weight of the insect. D Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.
D
If the mixed populations were cultured for an additional 25 days, which of the following predictions would be consistent with the data? A Both populations would stabilize at a small size. B Both populations would stabilize at a large size. C Both populations would be eliminated from the culture. D One population would stabilize at a large size, and the other population would be eliminated from the culture.
D
Members of which species are herbivores? A A B B C C D D E E
D
The CFTRCFTR protein is made up of 1,4801,480 amino acids linked together in a chain. Some humans produce a version of the CFTRCFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain. Which of the following best predicts how the amino acid deletion will affect the structure of the CFTRCFTR protein? A It will have no observable effect on the structure of the CFTRCFTR protein. B It will affect the primary structure of the CFTRCFTR protein, but the other levels of protein structure will not be affected. C It will affect the secondary and tertiary structures of the CFTRCFTR protein, but the primary structure will not be affected. D It will affect the primary, secondary, and tertiary structures of the CFTRCFTR protein.
D
The fossil record indicates that in some cases reasonably well-defined species appear suddenly and remain unchanged for a long time before they become extinct. This phenomenon is referred to as A allopatric speciation B sympatric speciation C phyletic gradualism D punctuated equilibrium E parallel evolution
D
The graph above represents the number of individuals in a population of wolves and in a population of moose observed in the same isolated geographic area over a 40-year period, from 1955 through 1995. Which of the following statements about the two populations is best supported by the information presented in the graph? A The reproductive rate of the wolves was greater than the reproductive rate of the moose. B Mutualism allowed the two populations to reproduce while occupying the same ecological niche. C Speciation occurred when the two populations became reproductively isolated from each other. D The wolves were predators of the moose, which were otherwise reproductively successful.
D
The table above shows the types and properties of nitrogencontaining wastes produced by several vertebrates. Which of the following is the best evolutionary explanation of the data? A The data support convergent evolution for nitrogen excretion in organisms occupying dramatically different environmental niches. B The nitrogenous waste excreted by each vertebrate is the result of evolutionary adaptations that have decreased vulnerability to predators. C Nitrogen homeostasis in terrestrial vertebrates reflects an adaptation for more frequent and higher-volume urination than that occurring in aquatic vertebrates. D Ammonia secretion requires a large volume of water and was therefore selected against in terrestrial vertebrates.
D
There is strong evidence that two species of cliff-dwelling birds have nested in the same environment and fed in the same water for thousands of years, with each having stable population sizes. Based on this information, which of the following statements is the best conclusion? A One species is a better diver than the other species is. B The two birds compete for food. C One species will displace the other. D The two birds have different ecological niches that allow coexistence. E One species eats a more diverse diet than the other does.
D
When hydrogen ions are pumped out of the mitochondrial matrix, across the inner mitochondrial membrane, and into the space between the inner and outer membranes, the result is A damage to the mitochondrion B the reduction of NAD C the restoration of the Na-K balance across the membrane D the creation of a proton gradient E the lowering of pH in the mitochondrial matrix
D
Which of the following conclusions is most clearly supported by the representations of nucleic acid #1#1 and nucleic acid #2#2 ? A Nucleic acid #1#1 contains only purines, whereas nucleic acid #2#2 contains only pyrimidines. B Nucleic acid #1#1 contains the sugar ribose, whereas nucleic acid #2#2 contains the sugar deoxyribose. C Nucleic acid #1#1 contains positively charged phosphate groups, whereas nucleic acid #2#2 does not. D Nucleic acid #1#1 contains adenine-thymine base pairs, whereas nucleic acid #2#2 does not.
D
Which of the following correctly identifies the dependent variable and the independent variable for the experiment? A The independent variable is the percent of squirrels responding, and the dependent variable is the type of alarm call. B The independent variable is the percent of squirrels responding, and the dependent variable is the type of response. C The independent variable is the group of squirrels, and the dependent variable is the percent of squirrels responding. D The independent variable is the type of alarm, and the dependent variable is the percent of squirrels responding.
D
Which of the following is an accurate description of the process shown in Figure 1 ? A The linking of amino acids with an ionic bond as an initial step in the protein synthesis process B The formation of a more complex carbohydrate with the covalent bonding of two simple sugars C The hydrolysis of amino acids with the breaking of covalent bonds with the release of water D The formation of a covalent peptide bond in a dehydration synthesis reaction
D
Which of the following is most directly responsible for water's unique properties? A It contains oxygen atoms. B It contains hydrogen atoms. C It is an ionic compound. D It forms hydrogen bonds. E It is nonpolar.
D
Which of the following observations best represents a mutualistic relationship? A Some bacteria and fungi obtain their nutrients by enzymatically digesting larger organisms. B Chloroplasts in green algae provide sugars for use in cellular metabolism. C Hermit crabs utilize empty sea snail shells to protect themselves from predators. D Flowers produce nectar that bees gather to make honey, and in the process the bees pollinate the flowers.
D
Which of the following observations best supports the hypothesis that a large object collided with Earth in a period of time associated with a mass extinction? A A species found only in Australia resembles a species found only in North America. B An analysis of radiation reaching Earth from outer space suggests that water might have existed on distant planets. C A fossil of an extinct species of mammal is found to have morphological characteristics that are similar to those of a living nocturnal mammal. D Iridium, which is common in meteorites but rare on Earth, is found in sedimentary rock that contains the last appearance of many species in the fossil record.
D
Which of the following questions about the origin of life on Earth is most scientifically testable? A Why were the earliest life-forms created using only twenty amino acids? B Did life originate to make the universe a better place? C Was catalytic RNA used by ancient organisms as a stepping stone to acquire protein enzymes? D Can simple organic molecules form spontaneously in an oxygen-free atmosphere?
D
Which of the following statements best describes how molecules released by the fish become nutrients for the plants? A The carbon dioxide molecules released by the fish are converted by the bacteria to oxygen atoms, which are used by the plants to make water molecules. B The oxygen molecules released by the fish are converted by the bacteria to ammonia molecules, which are used by the plants to make lipids and fatty acids. C The nitrites released by the fish are converted by the bacteria to carbon dioxide molecules, which are used by the plants to make carbohydrates. D The ammonia molecules released by the fish are converted by the bacteria to nitrates, which are used by the plants to make proteins and nucleic acids.
D
Which of the following statements best expresses the concept of punctuated equilibrium? A Small variations gradually accumulate in evolving lineages over periods of millions of years. B Random mating ensures that the proportions of genotypes in a population remain unchanged from generation to generation. C Stability is achieved when selection favors the heterozygote, while both types of homozygotes are at a relative disadvantage. D Evolutionary changes consist of rapid bursts of speciation alternating with long periods in which species remain essentially unmodified. E Under competition for identical resources, one of the two competing species will be eliminated or excluded.
D
Which statement is the most accurate description of the reaction shown in Figure 1? A It represents monomers linked by dehydration synthesis. B It represents a polypeptide chain that folds to form the tertiary structure. C It represents a polypeptide chain that is denatured into the primary structure. D It represents a polypeptide chain that is broken down through a hydrolysis reaction.
D
A parasite may be described as an organism that derives nourishment from another living organism and A becomes necessary to the life of the host B is neutral in its effect on the host C benefits the host nutritionally D provides a supportive structure for the host E harms the host in the process
E
All of the following statements concerning characteristics of predator-prey relationships are correct EXCEPT: A A rise in the population of prey is often followed by a rise in the population of predators. B A rise in the population of predators is followed by a decrease in the populationof prey. C Camouflage is an adaptation that protects prey. D The production of large numbers of offspring within very short periods of time ensures the survival of some prey populations. E The population of predators most often eliminates the population of prey.
E
All of the following were likely present on the primitive Earth during the evolution of self-replicating molecules EXCEPT A amino acids and nucleotides B nitrogen C simple carbohydrates D freestanding liquid water E an O2-rich atmosphere
E
An overlap in the niches of two species will most frequently result in A interspecific cooperation B a hybridization of species C a mutualistic symbiotic relationship D an increase in the biomass E interspecific competition
E
The amino acid sequence of cytochrome c is exactly the same in humans and chimpanzees. There is a difference of 13 amino acids between the cytochrome c of humans and dogs, and a difference of 20 amino acids between the cytochrome c of humans and rattlesnakes. Which of the following statements is best supported by these data? A Rattlesnakes apparently gave rise evolutionarily to the dog, chimpanzee, and human. B Cytochrome c apparently has an entirely different function in rattlesnakes than in mammals, which explains the difference in the number of amino acids. C Cytochrome c is not found universally in animals. D Cytochrome c from a rattlesnake could function in a dog, but not in a chimpanzee. E The human is apparently more closely related to the chimpanzee than to the dog or rattlesnake.
E
The condition in which there are barriers to successful interbreeding between individuals of different species in the same community is referred to as A latent variations B sterility C structural differences D geographic isolation E reproductive isolation
E
The population would be most likely to remain at the level shown at Q under which of the following conditions? A All predators are eliminated. B The population size is well below its carrying capacity. C Euglena is a primary producer. D Euglena is a primary consumer. E Environmental conditions do not fluctuate.
E
The synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct? A ATP B Oxygen C Carbon dioxide D Urea E Water
E
Which of the following best describes the functionof the coenzymes NAD+ and FAD in eukaryoticcellular respiration? A They participate in hydrolysis reactions byaccepting protons from water molecules. B They participate directly in thephosphorylation of ADP to ATP. C They serve as final electron acceptors in theelectron transport chain. D They aid vitamins such as niacin in the breakdownof glucose. E They accept electrons during oxidation-reductionreactions.
E
Which of the following best explains why there are seldom more than five trophic levels in a food chain? A Most carnivores function at more than one trophic level. B Trophic levels above this number contain too many individuals. C Top carnivores are too few in number to prey effectively. D The ecosystem contains too much biomass. E Energy is lost from each trophic level.
E
Which point on the curve in the diagram above best represents the carrying capacity of the environment for the population shown? A A B B C C D D E E
E