Unit 7 Collegeboard MCQ
Which of the following is closest to the frequency of the MC1R D allele in the Tule Mountain population? Responses A 0.03 B 0.06 C 0.94 D 0.97
A 0.03
Which of the following best describes the process responsible for the change in the percent of tuskless female elephants in the Gorongosa National Park population shown in Figure 1 ?
A Human hunting of elephants with tusks between 1977 and 1992.
Based on the data in Figure 1, which of the following best describes the concept illustrated?
A Parental pairs with a specific beak depth had the highest reproductive fitness.
In addition to the ABO blood groups, humans have an MN blood type system in which the M and N alleles are codominant to one another. A group of scientists found that in one population the frequency of the M allele was 0.82, and the frequency of the N allele was 0.18. Assuming that the population is in Hardy‑Weinberg equilibrium, which of the following is the expected frequency of individuals with the genotype ��? Responses A 0.148 B 0.295 C 0.640 D 0.672
B 0.295
Scientists want to determine the age of four fossil specimens. They have analyzed the fossils and gathered the data shown in Table 1. Which of the specimens indicated in the table is the oldest? Responses A Specimen 1 B Specimen 2 C Specimen 3 D Specimen 4
D Specimen 4
The researchers determined that the East lava flow population is not in Hardy-Weinberg equilibrium. Which of the following best explains why the population is not in Hardy-Weinberg equilibrium? Responses A The presence of heterozygotes for the MC1R D gene in the East lava flow population indicates that mating is occurring randomly between mice with different coat colors. B The selective pressures on the East lava flow population are not strong enough to maintain Hardy-Weinberg equilibrium. C The East lava flow population does not experience migration, which is a required condition for Hardy-Weinberg equilibrium. D The presence of MC1R D alleles in the East lava flow population is an indication of gene flow from mice populations living on light granite rocks.
D The presence of MC1R D alleles in the East lava flow population is an indication of gene flow from mice populations living on light granite rocks.
Which of the following is an appropriate null hypothesis regarding the phenotypic frequencies of this population of salamanders before and after the flood? A More black salamanders survived because they could better hide from predators on the dark muddy soil, so the frequency of the black phenotype significantly increased in the population after the flood. B Fewer light-brown salamanders survived because they had a reduced chance of finding mates due to the high water levels, so the frequency of the light-brown phenotype in the population decreased after the flood. C More dark-brown salamanders migrated to a new, drier area because of the flood and fewer of them remained in the original habitat, so the frequency of dark-brown salamander significantly decreased in the population after the flood. D The proportions of black, dark-brown, and light-brown salamanders before and after the flood are not significantly differe
D The proportions of black, dark-brown, and light-brown salamanders before and after the flood are not significantly different, and any observed differences are due to random chance.
The biologist discovered that from 1988 to 1993 the average beak size declined to pre 1981 levels. The reversal in beak size from 1988 to 1993 was most likely related to which of the following events
b. The end of the drought
Competition for food would probably be most severe between two.....
b. closely related species in similar niches
Which of the following procedures was most likely followed to determine the change in beak size
c. The beak size in a large number of finches was meaaured every year from 1981 to 1987
The most abundant tobacco species in the population's habitat has a nectary tube that is 5cm long. Over the next year, a virus attacks and rapidly kills almost all plants of the tobacco species. A closely related species of tobacco that is resistant to the virus becomes established during that same year. The nectary tube in the resistant species averages 7.5cm. Scientists monitored the area for the next five years to determine how this change affected the moth population. Which of the following best describes the expected distribution of proboscis size of the moths at the end of the five‑year study? A B C D
B
A 100 acre woodlot was observed for the last forty years. Five plant species (1 through 5) were surveyed, with the results shown in Table 1. Some researchers claim that the decrease in plant species richness of this woodlot is unrelated to human activities over the last forty years. Which of the following would be an appropriate alternative hypothesis? A Interspecific competition caused the extinction of species 4 and 5. B The woodlot environment is arid and species 1 and 2 are well-adapted to conserve water. C The woodlot is shaded, with little direct sunlight, and species 3, 4, and 5 are shade-intolerant canopy trees. D During the last few decades, tall buildings have been built around the woodlot, and species 3, 4, and 5 are shade‑intolerant plants
D During the last few decades, tall buildings have been built around the woodlot, and species 3, 4, and 5 are shade‑intolerant plants
Which of the following statements Might best explain the increase in average beak size in the Finch population during the drought
a. Finches with bigger beaks are better able to crack thick walled seeds and produce more surviving offspring
Which of the following best describes the mechanism behind the change in beak size in the Finch population
b. A change in gene frequencies in the Finch population due to selective pressure form the environmental change
Which of the following best describes the importance of the number of amino acid differences indicated in Table 1 ?
b. They reflect the number of base pair changes in the DNA.
In Darwinian terms, the fittest individuals of a species are those that
b. reproductive success
Mollusk fossils were excavated and collected from a coastal cliff. Scientists studying the fossils observed patterns of changing shell shape in the mollusks. The scientists identified a period of stability or stasis, followed by rapid change, and then stasis again with regard to shell shape. Which of the following statements best predicts the result of a comparison between the fossils found before and after the period of rapid change? a. The same species will be found in both static periods, but they will have different shell shapes. b. The same species will be found in both static periods, but the species in the second static period will have smaller shells due to the stress of undergoing rapid change. c. Most of the species found in the first static period will be absent in the second static period. d. Most of the species found in the second static period will resemble each other
c. Most of the species found in the first static period will be absent in the second static period.
Which of the following data sets is most likely to provide reliable information about the evolutionary relationships among these three snail species?
d. Location of fossils and shell orientation
Owls (primary predators of rock pocket mice) are nocturnal visual predators that are able to distinguish effectively between dark and light colors in low-light conditions. Which of the following best explains the relationship between coat color and predation rate in the rock pocket mouse population on the lava flow rocks with respect to the different coat color phenotypes? Responses A A dark coat color provides camouflage to mice on the lava flow rocks; therefore, mice with dark coats have a lower predation rate in that habitat. B At night, predators have reduced vision, so there is no relationship between coat color and predation rate on rock pocket mice. C A dark coat color reflects less light and therefore mice with dark coats have a lower predation rate. D A light coat color reflects more light and therefore mice with light coats have a lower predation rate.
A A dark coat color provides camouflage to mice on the lava flow rocks; therefore, mice with dark coats have a lower predation rate in that habitat.
Of the following, which is the best next step for the researchers to best determine the long-term effectiveness of these insecticides with regards to the development of resistance? Responses A Continue treating the three insect populations with the same insecticides and determine whether their efficiencies decline significantly after several generations. B Add an additional treatment group to the experiment to measure the effectiveness of another insecticide (Insecticide #3) over several generations. C Set up a new experiment in which these insects are sprayed with two different insecticides to see if they are more effective than Insecticides #1 and #2. D Spray these insecticides on a different species of insect (whose genotypes are also known) to determine its effectiveness on insects that are not pests.
A Continue treating the three insect populations with the same insecticides and determine whether their efficiencies decline significantly after several generations
Whales, bony fishes, and cartilaginous fishes all have similar adaptations that enable them to live in the ocean. Figure 1 shows the phylogenetic relationships of selected vertebrates. Based on the phylogenetic relationships shown in Figure 1, which of the following best explains the similarities exhibited by whales, bony fishes, and cartilaginous fishes? A Convergent evolution, because these organisms do not share a recent common ancestor. B Adaptive radiation, because all three groups evolved from a unique, shared common ancestor from the cartilaginous fishes group. C Mutation, because the shared traits can be traced back to a shared recent common ancestor. D Founder effect, because all three groups formerly existed together as one population that then was disrupted, causing speciation.
A Convergent evolution, because these organisms do not share a recent common ancestor.
Students created a model showing one possible mechanism for speciation in which a geographic barrier separated one large population into two smaller populations, A and B. Over time, populations A and B developed into two distinct species. The model is shown in Figure 1. Which of the following best describes what occurred during the periods indicated by the arrows? A Natural selection acted on variation that was present in both populations A and B, and the lack of gene flow eventually led to the formation of two new species. B Population B was separated for a longer time from the original population than population A was, and population B evolved into a more distinct new species than population A did. C Gene flow between populations A and B maintained sufficient variation in both gene pools to facilitate the development of two distinct species. D In response to different environments, populations A and B experienced d
A Natural selection acted on variation that was present in both populations A and B, and the lack of gene flow eventually led to the formation of two new species.
In a particular region, a species of lizard lives in the lowlands. Even though there are numerous mountains in the region, the climate on the mountains is too cold for the lizards to survive. Scientists are concerned that the lowlands will become much warmer by the end of the twenty-first century and will become unsuitable for this lowland lizard species. Which of the following best predicts the impact on the lizard species if there is a gradual increase in the average temperatures found in both the lowlands and mountains in this region? A Some lizards will migrate to new habitats in the mountains and become isolated, leading to allopatric speciation. B The species will undergo artificial selection, as the genes will adapt to warmer temperatures. C The species will experience a genetic bottleneck, and sympatric speciation will result in the development of several new species. D The lizards will hybridize with a diffe
A Some lizards will migrate to new habitats in the mountains and become isolated, leading to allopatric speciation.
Which of the following best represents the next step the researchers should take with respect to experimental design? A Group 1: high dose of streptomycin + low dose of additional antibiotic Group 2: low dose of streptomycin + high dose of additional antibiotic B Group 1: low dose of streptomycin + no dose of additional antibiotic group 2: low dose of streptomycin + low dose of additional antibiotic C Group 1: no dose of streptomycin + no dose of additional antibioticGroup 2: low dose of streptomycin + low dose of additional antibiotic D Group 1: low dose of streptomycin + low dose of additional antibioticGroup 2: high dose of streptomycin + high dose of additional antibiotic
B Group 1: low dose of streptomycin + no dose of additional antibiotic group 2: low dose of streptomycin + low dose of additional antibiotic
The peppered moth, Biston betularia was generally white in color with black speckles. Over time a more solid black moth became the more common variety. Which of the following best explains the relationship between wing pigmentation and the coloration of a moth's surroundings? Responses A The frequencies of the different phenotypes in the moth population changed randomly due to genetic drift. B If the surroundings of the peppered moth became darker, those backgrounds conferred a selective advantage to a black variety, as described by natural selection. C There was a gene flow of the black variety, spreading it throughout the moth's normal range. D The black variety was a nineteenth century mutation, dominant to the peppered variety. The allele for the peppered trait, being recessive, decreased in frequency over time
B If the surroundings of the peppered moth became darker, those backgrounds conferred a selective advantage to a black variety, as described by natural selection.
Based on the data in Table 1, which of the following best describes the relationship between the MC1R D gene and coat color in the Carrizozo, New Mexico, rock pocket mouse population? Responses A The MC1R D allele is responsible for dark coat color in the Carrizozo population and likely spread from the Arizona population through migration. B The MC1R D allele is not responsible for dark coat color in the Carrizozo population, so the dark coat color is likely a result of convergent evolution. C The MC1R D allele is absent from the Carrizozo population, so all the mice in this population must have coats that are light in color. D The MC1R D allele is absent from the Carrizozo population because of different environmental pressures in the Carrizozo population.
B The MC1R D allele is not responsible for dark coat color in the Carrizozo population, so the dark coat color is likely a result of convergent evolution.
The distribution of four populations of giant kangaroo rats, Dipodomys ingens, living on the same island when it was first surveyed in 1789 are shown in Figure 1. In 1852, there was a large earthquake which altered the island's geography, as shown in Figure 2. The island was surveyed again in 2015, and scientists determined that the giant kangaroo rats originally in population A are now to be considered as a new species Which of the following best explains the mechanism that caused this speciation event in the giant kangaroo rats of population A? A The animals in population A were exposed to different predators and had to modify their fur color to be better camouflaged. B The animals in population A were reproductively isolated from those in populations B, C, and D. C The animals in population A accumulated fewer genetic mutations, adapting to their microclimate. D The animals in population A mate at different time
B The animals in population A were reproductively isolated from those in populations B, C, and D.
A current challenge for doctors involves the bacterial strain Clostridioides difficile, which no longer responds to traditional antibiotic treatments.Which of the following best explains why this particular strain of bacteria is resistant to antibiotic treatment? A. Mutations creating new alleles occur more frequently in this species of bacteria than in other species. B. The bacteria have high genetic variability and high reproductive rates. C. Crossing over during meiosis increased genetic variability in the bacteria. D. The bacteria are able to recognize and destroy the antibiotics by breaking them down extracellularly.
B. The bacteria have high genetic variability and high reproductive rates.
Which of the following could best explain the change in fur color distribution, as shown in the table above?
B. The field was primarily composed of light-colored soil and little vegetation, affording gray mice protection from predators
Which of the following best describes the processes occurring between the mouse populations and their environments? Responses A Natural selection favors the mice with the dark coat color, causing the mice in all of the populations to be better adapted. B Natural selection favors the mice with the light coat color, causing the mice in all of the populations to be better adapted. C Dark color is selected for in mice from the West, Mid, and East populations. D Light color is selected for in mice from the West, Mid, and East populations.
C Dark color is selected for in mice from the West, Mid, and East populations.
The bird, Parus major, is commonly found in man-made habitats. During the summer these birds primarily feed on insects, and in the winter, when insects are scarce, they forage in gardens and bird feeders for seeds, nuts, and berries. Recently, climate change has led to a decrease in food available from gardens, and scientists have observed that the average beak length of the birds has increased.Which of the following best explains the directional shift in beak length in these birds? A Longer beaks allow the birds to better fend off predators. B Longer beaks increase the fitness of the birds in wild habitats. C Longer beaks allow the birds to better access seeds in bird feeders. D Longer beaks decrease the fitness of the birds in wild habitats.
C Longer beaks allow the birds to better access seeds in bird feeders.
Which of the following experiments would specifically determine which gene is responsible for ceftazidime-avibactam sensitivity in P. aeruginosa ? A Clone the three deleted genes from a wild-type P. aeruginosa strain, and insert these sequences into the mutant bacterial strains to restore sensitivity to ceftazidime-avibactam. B Delete genes that are homologous to the three deleted genes in other bacterial species, and determine if doing so also confers ceftazidime-avibactam resistance in those bacteria. C Perform gene knockout (targeted mutation) of either the hmgAℎ, galU, or mexXY gene on separate cultures of the wild-type P. aeruginosa. For each individual mutant, determine whether or not ceftazidime-avibactam resistance has occurred. D Perform gene knockout (targeted mutation) of both the hmgAℎ and galU genes of the wild-type P. aeruginosa in a single culture, and then determine if ceftazidime-avibactam resist
C Perform gene knockout (targeted mutation) of either the hmgAℎ, galU, or mexXY gene on separate cultures of the wild-type P. aeruginosa. For each individual mutant, determine whether or not ceftazidime-avibactam resistance has occurred.
Because cheetahs, Acinonyx jubatus, experienced a bottleneck event about ten thousand years ago, living cheetahs exhibit very little genetic variation compared to other living species of large cats. Which of the following principles best justifies a claim that cheetahs, compared to other large cats, have a relatively low resilience to environmental perturbations? A A captive population of cheetahs kept in a confined area will have a greater risk of contracting and passing on a virus. B When a population is reduced, new niches become available in the environment, which can trigger adaptive radiation. C Populations with little genetic diversity are less likely to contain individuals that can withstand different selective pressures. D Populations with low genetic diversity are more likely to contain individuals that can withstand different selective pressures.
C Populations with little genetic diversity are less likely to contain individuals that can withstand different selective pressures.
The California newt, Taricha torosa, lives in the coastal areas around Los Angeles. Which of the following is a valid null hypothesis relating fitness to survival of a bottleneck event in a coastal area where a small, isolated population of California newts resides? A Only those salamanders with the lowest evolutionary fitness will be eliminated by the bottleneck effect, lowering the allelic frequencies of their traits. B Only those salamanders with the highest evolutionary fitness will survive the bottleneck event, raising the allelic frequencies of their traits. C Surviving the bottleneck event will be random, so any change in the allelic frequencies of the salamander population is not attributed to fitness. D Surviving the bottleneck event will be random, so there will be no changes to the allelic frequencies due to the bottleneck event.
C Surviving the bottleneck event will be random, so any change in the allelic frequencies of the salamander population is not attributed to fitness.
In eastern gray squirrels, Sciurus carolinensis, the allele for black fur (B)(�) is dominant to the allele for gray fur (b)(�). In a particular population of gray squirrels, 64% have black fur and 36% have gray fur. A researcher calculated the allelic frequencies to be B=0.4�=0.4 and b=0.6�=0.6. Five years later, the researcher returned to the location and determined the allelic frequencies within the squirrel population to be B=0.6�=0.6 and b=0.4�=0.4. Which of the following could best explain the increase in the frequency of the B� allele in the population after five years? A The frequency of the B� allele increased because it is the dominant allele.BThe frequency of the B� allele increased because squirrels with gray fur exhibited greater fitness. C The frequency of the B� allele increased due to the selective pressures of the environment. D The frequency of the B� allele increased because b
C The frequency of the B� allele increased due to the selective pressures of the environment.
The researchers built an enclosure to prevent migration into and out of the O'Neill rock pocket mouse population for a period of two years. Which of the following best predicts the effect of the enclosure on the O'Neill population? Responses A The O'Neill population will rapidly evolve into a separate species. B The O'Neill population will become less diverse due to the bottleneck effect. C The frequency of the MC1R D allele will decline due to natural selection. D One of the alleles for the MC1R D gene will become fixed due to genetic drift.
C The frequency of the MC1R D allele will decline due to natural selection.
Some plant species flower in response to increasing daily temperatures in the spring. Many of these species rely on pollinators that migrate based on changes in day length and the position of the Sun. The current global warming trend is placing new selective pressures on the species involved in these relationships. Which of the following best explains the impact of these new selective pressures on the organisms involved? Responses A If the environment for the plant species becomes too warm, the pollinators will no longer migrate to that area in the spring, continuing on to a more northern environment instead. B The warmer temperatures will lead to a drier environment, so the plants will no longer produce enough nectar to attract the pollinators. C The plant species will flower earlier in the spring in response to rising temperatures before the arrival of the pollinators, so seeds will not be produced. D Migrating pol
C The plant species will flower earlier in the spring in response to rising temperatures before the arrival of the pollinators, so seeds will not be produced.
Which of the following best explains why the brown-feathered phenotype in tawny owls has increased over the past 28 years?A Since the brown genotype is dominant, it will eventually eliminate the recessive gray genotype from the population. B Darker feather color in tawny owls makes them less visible to predators as they sit in the trees. C With milder winters, the advantage of gray feathers that blend into a snowy environment has decreased. D The directional selection toward a darker phenotype is random and likely due to a bottleneck event.
C With milder winters, the advantage of gray feathers that blend into a snowy environment has decreased.
Which of the following statements best explains how a condition of Hardy-Weinberg equilibrium results in a population that exhibits stable allele frequencies (i.e., a nonevolving population) ? A Large populations are not subject to natural selection. B Random mating prevents gene flow from changing allele frequencies. C Without migration or mutation, new alleles cannot be introduced to the population. D In the absence of selection, allele frequencies in a population will not change.
C Without migration or mutation, new alleles cannot be introduced to the population.
Figure 1 describes a possible scenario, known as the RNA World Hypothesis, that could have led to the evolution of our modern-day genetic material. This hypothesis states that the first genetic material was RNA, not DNA, and a transitional period led to the emergence of DNA as the storage molecule for genetic material. Which of the following is an alternative hypothesis that can be tested to support the RNA World Hypothesis? A A protein template that matches proteins found on the primitive Earth added to a mixture of deoxyribonucleotides will produce double-stranded DNA molecules. B Double strands of DNA placed in a harsh environment will unwind and form RNA molecules for long term information storage. C A pool of amino acids can spontaneously form into single‑stranded RNA, which would then code for proteins. D A mixture of ribonucleotides such as adenine and uracil will spontaneously form single-stranded chains
D A mixture of ribonucleotides such as adenine and uracil will spontaneously form single-stranded chains of RNA.
Catalase is a protein enzyme that catalyzes the breakdown of hydrogen peroxide (H2O2) into water and oxygen gas in the cells of many living organisms. Students used an online database, which used the structure of catalase from different species, to generate the phylogenetic tree shown in Figure 1. Which of the following student claims is best supported by the data provided? Responses A Mushrooms and potatoes are most closely related, since the node they share gave rise to all of the other organisms. B Cattle are equally related to pigs and sheep, because the phylogeny places cattle between pigs and sheep. C Yeast and mushrooms are the most closely related, because they are both fungi. D Cattle and sheep are separated by only one node, and they are separated from the other organisms by more than one node.
D Cattle and sheep are separated by only one node, and they are separated from the other organisms by more than one node.
Figure 1 shows some major structural changes between a typical prokaryotic cell, the first eukaryotic common ancestor, and the last eukaryotic common ancestor. Based on the information provided in the figure, which of the following best describes how membrane-bound organelles provided unique evolutionary advantages to the last eukaryotic common ancestor? Responses A Cells with nuclear membranes were better able to protect their genetic material against damage. B Cells with flagella were better able to find food and escape predators. C Cells with ribosomes were better able to produce proteins needed for a variety of metabolic functions. D Cells with mitochondria were able to utilize metabolic energy more efficiently.
D Cells with mitochondria were able to utilize metabolic energy more efficiently.
Which of the following experiments would be most appropriate to determine whether populations of S. aureus are continuously adapting in order to obtain iron from hosts more effectively? A Grow S. aureus in media with macaque hemoglobin and abundant free iron. Record bacterial growth over time and compare it to growth of the original population. B Culture S. aureus bacteria with hemoglobin from a mixture of host species. Then transfer the bacteria to media with a known effective antibiotic and record bacterial growth. C Sequence the genes of different S. aureus strains and construct a cladogram representing their relatedness. D Culture S. aureus bacteria with hemoglobin from a novel host species as the only source of iron for many generations, then compare protein structure from bacteria in this culture with bacteria from the original culture.
D Culture S. aureus bacteria with hemoglobin from a novel host species as the only source of iron for many generations, then compare protein structure from bacteria in this culture with bacteria from the original culture.
Populations J1 through J5 are located in Jasper County. Populations M1 through M5 are located in Marion County. Numbers above 0.125 indicate a high degree of relatedness. Based on the data in table 1, which of the following best provides evidence to support this claim? Responses A The Marion County populations have a higher rate of mutation than the Jasper County populations, as evidenced by the higher degrees of relatedness. B The Marion County populations are less stable because they are smaller than the Jasper County populations. C The M2 population has a higher degree of relatedness than the M1 population, meaning that it has more genetic diversity. D The M4 and M5 populations have the lowest genetic diversity of all populations.
D The M4 and M5 populations have the lowest genetic diversity of all populations.
In humans, one allele of the APOE gene, called APOE-ε22, can result in a high tolerance of cholesterol. Cholesterol is a vital substance for humans but may lead to heart disease in an older adult with a history of high cholesterol diets. High cholesterol diets are becoming more prevalent in the United States. Currently only about 2% of humans carry the APOE-ε22 allele.Which of the following states a valid null hypothesis about the future distribution of APOE alleles in future generations in the United States? A The APOE-ε22 allele was the result of chance mutations so it is not possible to predict how its frequency will change in the future. B As high cholesterol diets become more common in the United States, individuals with the APOE-ε22 allele will have a better survival rate from heart disease than those without the allele, so the allele will increase in frequency. C The low frequency of the APOE-ε22 allele
D The variant protects an individual from a condition that is only common among humans beyond reproductive age, so the frequency of the allele will likely not change much in the future because it is not influenced by natural selection.
Geologic events such as mountain building can directly affect biodiversity. The Sino‑Himalayan fern, Lepisorus clathratus is widely distributed on the Qinghai‑Tibetan plateau. If geologic events lead to a series of new mountain ranges that divide the plateau into several discrete valleys, which of the following best describes how the L. clathratus population would be affected? a. Geographic isolation will create separate gene pools, leading to speciation over time. b. Gene flow will be reduced by sexual selection and polyploidy. c. Chance events will cause allele frequencies to fluctuate unpredictably from one generation to the next. d. Ferns reproduce asexually, so there will be no impact on the gene pool of the species.
a. Geographic isolation will create separate gene pools, leading to speciation over time.
Antibiotics can be used to kill the specific pathogenic bacterium, Mycobacterium tuberculosis, that causes tuberculosis. The appearance of antibiotic-resistant strains has made it more difficult to cure M. tuberculosis infections. These antibiotic-resistant bacteria survive and pass on the genes to their offspring, making the resistant phenotype more common in the population.DNA analysis indicates that the genes for antibiotic resistance are not normally present in bacterial chromosomal DNA. Which of the following statements best explains how the genes for antibiotic resistance can be transmitted between bacteria without the exchange of bacterial chromosomal DNA?
b. The genes for antibiotic resistance are located on a plasmid that can be passed to neighboring bacteria.
