unit 7- ap bio optional multiple choice
A researcher is studying two different species. Which of the following sets of observations would best support the claim that the two species have structural similarities as a result of convergent evolution?
A GeneticSimilarityFunction ofStructureForm ofStructureLowSameDifferent
The researchers performed a chi-square analysis to test their hypothesis. Assuming the researchers use a significance level of 0.050.05, which of the following is closest to the critical value the researchers should use in the chi-square analysis? A 3.84 B 5.99 C 7.82 D 9.49
A 3.84
Many species of corals are threatened by the increasing temperatures and decreasing pHpH of ocean waters. One species, Stylophora pistillata, has been found to thrive in water that is warmer and has a lower pHpH than the water that corals typically thrive in. Additionally, researchers have found that the tolerance for the new water conditions is heritable. Which of the following statements best explains the changes seen in S. pistillata in response to the changing water conditions? A The corals' adaptation is an example of natural selection because the tolerance is in response to a changing environment and has a genetic basis. B The corals' adaptation is an example of the founder effect because the majority of corals do not have a tolerance for warmer water. C The corals' adaptation is an example of genetic drift because the change was a chance event and not the result of selection in response to environmental change
A The corals' adaptation is an example of natural selection because the tolerance is in response to a changing environment and has a genetic basis.
A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds. 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. B Finches with bigger beaks can attack and kill finches with smaller beaks. C Finches with bigger beaks possess more powerful flight muscles and are able to find more food. D Finches that crack large seeds develop larger beaks over time.
A Finches with bigger beaks are better able to crack thick-walled seeds and produce more surviving offspring.
The graph above shows the distribution of beak depth in a finch population that had been living on an island under conditions of normal rainfall. During a subsequent drought, the small seeds normally eaten by the finches were less available. Most of the available seeds were large seeds that could be eaten most easily by finches with deep beaks. Which of the following graphs best predicts the distribution of beak depth in the finch population after several years of drought?
A Graph showing beak sizes going upward over time
A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds. Which of the following best describes the mechanism behind the change in beak size in the finch population? A The formation of two new finch species from a single parent species B A change in gene frequencies in the finch population due to selective pressure from the environmental change C A new allele appearing in the finch population as a result of mutation D The achievement of dynamic equilibrium in the finch population as a result of homeostasis
B A change in gene frequencies in the finch population due to selective pressure from the environmental change
Poaching is the illegal hunting or capturing of wild animals. Both male and female African elephants have tusks that are a significant source of ivory used for ornaments and jewelry. Assuming that the size of the tusks is heritable, which of the following is the most likely long-term effect of poachers targeting African elephants with large tusks? A An increase in average tusk size because of the need to provide more ivory for the poaching hunters B A decrease in average tusk size because elephants with large tusks are less likely to survive to reproduce C An increase in average tusk size to provide the elephants with a defensive mechanism against poachers D A decrease in average tusk size to reduce the energy investment in the tusks
B A decrease in average tusk size because elephants with large tusks are less likely to survive to reproduce
Which of the following scientific questions will best help researchers determine when the nontaster allele arose in the evolutionary history of the selected primates? A How does the nontaster allele contribute to individual fitness? B Does the nontaster allele exist in any nonhuman primate populations? C What caused the mutations in the TAS2R38 gene? D How do the mutations in the nontaster allele affect the structure of the resulting protein?
B Does the nontaster allele exist in any nonhuman primate populations?
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 Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life
Pesticides are chemicals that are often sprayed on crops to kill plant-eating insects, preventing damage to the crops. While pesticides are effective initially, many researchers claim that any single pesticide will see reduced effectiveness in as little as ten to fifteen years. Which of the following best supports the claim by scientists that the pesticides will eventually lose their effectiveness? A Insects will evolve to avoid any plant sprayed with pesticides to increase their chances of survival. B Insects that are naturally resistant to the pesticide will survive and reproduce more than the insects that are sensitive to the pesticide. C The insects will build up a tolerance to the pesticides, and eventually the pesticide will not affect them. D The pesticides will increase the mutation rate in the insects, resulting in higher genetic diversity and higher survival rate.
B Insects that are naturally resistant to the pesticide will survive and reproduce more than the insects that are sensitive to the pesticide.
Which of the following combinations of flies showed the highest number of mating instances? A Males grown on maltose paired with females grown on starch B Males grown on starch paired with females grown on starch C Males grown on maltose paired with females grown on maltose D Males grown on starch paired with females grown on maltose
B Males grown on starch paired with females grown on starch
The hormone prolactin has varying effects in many different animal species. All vertebrates produce prolactin, which is involved in signal transduction pathways. In mammals, prolactin stimulates the production of milk in mammary glands. In fish, prolactin plays an important role in osmoregulation. In birds, prolactin is involved in lipid metabolism. Which of the following best explains the presence of prolactin in various vertebrate species? A Though all vertebrates produce prolactin, its varied uses indicate it arose as a result of convergent evolution and not as a result of common ancestry. B Prolactin is a homologous hormone because it has a common origin but different functions in various species. C Prolactin will bind only to intracellular receptors in animal species with phospholipid bilayers, so its effects are varied in different species. D Because of different receptors activating different signal transducti
B Prolactin is a homologous hormone because it has a common origin but different functions in various species.
For a population to be in Hardy-Weinberg equilibrium, certain conditions must be met. Which of the following best explains a characteristic of the fly populations that meets a condition of Hardy-Weinberg equilibrium? A The population size of the flies was very small, which increases the likelihood of random mutations having a greater impact. B Since the flies were confined in chambers, they did not experience any migration, so no new alleles were introduced through migration. C Flies have a relatively short generation time and therefore are more likely to pass mutations to the next generation. D The different food sources may have exerted selective pressure on the fly populations, giving an advantage to certain flies.
B Since the flies were confined in chambers, they did not experience any migration, so no new alleles were introduced through migration.
Blackcap birds (Sylvia atricapilla) migrate out of Germany before wintertime. Prior to the 1960s, all members of a particular blackcap population flew to Spain, which had an abundant natural food source. Now, some members of the same blackcap population fly to the United Kingdom, where food placed in feeders by humans is abundant. The blackcaps return to the same forests in Germany to nest during the breeding season. Some blackcaps that migrate to the United Kingdom have become distinguishable by certain physical and behavioral traits from blackcaps that migrate to Spain. Which of the following best predicts the effect on the blackcap population if humans in the United Kingdom continue to place food in feeders during the winter? A The blackcaps that migrate to Spain will selectively mate with the blackcaps that migrate to the United Kingdom, resulting in increased genetic variation in the blackcap population. B The b
B The blackcaps that migrate to the United Kingdom will become reproductively isolated from the blackcaps that migrate to Spain, resulting in speciation in the blackcap population.
In an experiment, 100 mice were released into a field to which no other mice had access. Immediately after their release, a representative sample of mice was captured, their fur color was recorded, and they were returned to the field. After twenty years, a representative sample of mice was captured and the distribution of fur color was again recorded. Which of the following could best explain the change in fur color distribution, as shown in the table above? A The allele for black fur color is unstable, and over twenty years most of the black fur alleles mutated to become alleles for gray fur. B The field was primarily composed of light-colored soil and little vegetation, affording gray mice protection from predators. C Sexual selection led to increased mating frequency of black and brown versus gray and brown. D The gray mice were harder to catch, and so were underrepresented in the twenty-year sample.
B The field was primarily composed of light-colored soil and little vegetation, affording gray mice protection from predators.
Which of the following claims is best supported by the data in Tables 1 and 2 ? A The population of flies has undergone sympatric speciation. B The flies have developed a form of behavioral preference that could lead to divergence. C A postzygotic barrier has evolved between the populations of flies that prevents the birth of viable offspring. D The flies have undergone allopatric speciation, since only flies from the same chamber mated.
B The flies have developed a form of behavioral preference that could lead to divergence.
A particular genetic disorder is associated with a single gene with two alleles. Individuals with two recessive alleles are affected. The prevalence of the disorder is 11 in 6,6006,600. Assuming the population is in Hardy-Weinberg equilibrium, which of the following is closest to the frequency of carriers in the general population? A 0.00015 B 0.01230 C 0.02430 D 0.98770
C 0.02430
Starch is a complex carbohydrate that is digested by the enzyme amylase. A mutation in the gene that encodes amylase prevents the digestion of starch. The inability to digest starch is an autosomal recessive trait. In a population of 1,0001,000 flies, 410410 were unable to break down starch. Which of the following is closest to the number of flies expected to be heterozygous for the amylase mutation assuming all conditions of Hardy-Weinberg equilibrium are met? A 0.13 B 0.36 C 0.46 D 0.64
C 0.46
Evolutionary biologists have observed variation in the average age and size of mature individuals in a population of small freshwater guppies. Guppies found in pools with pike cichlids— a predator fish that preys primarily on larger guppies—reproduce at a young age and are small at maturity. Guppies found in pools with killifish —a different predator fish that preys primarily on smaller guppies—reproduce at an older age and are larger at maturity. Which of the following predicts the most likely outcome of moving a population of guppies from a pool with pike cichlids to a pool with killifish? A The introduced guppy population will remain phenotypically similar to the original population because the killifish will not recognize them as prey. B Because the introduced population was in Hardy-Weinberg equilibrium, successive generations in the new population will continue to display the same allele frequencies as
C After many generations, the offspring of the introduced guppies will mature at an older age and larger size because of selective pressure from the new predator.
The brown anole (Anolis sagrei) is a species of lizard native to Cuba that has been introduced into the southeastern United States. The range of brown anoles in the United States has been expanding, and they are now competing with native green anoles (Anolis carolinensis). Some of the characteristics of the green and brown anoles are shown in Table 1. Based on the data in Table 1, which of the following best explains the observed differences in cold tolerance between brown anoles (A. sagrei) and green anoles (A. carolinensis) in the United States?
C Green anoles with greater tolerance for cold had greater reproductive success in areas with colder temperatures.
A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds. Which of the following procedures was most likely followed to determine the change in beak size? A A few finches were trapped in 1981 and again in 1987, and their beak sizes were compared. B The beak size in fifteen finches was measured in 1987, and the beak size in the original finches was determined by estimation. C The beak size in a large number of finches was measured every year from 1981 to 1987. D Finches were captured and bred in 1981, and the beak size of the offspring was measured.
C The beak size in a large number of finches was measured every year from 1981 to 1987.
Modern bananas originated from a cross between a tetraploid banana species and a diploid banana species. The product of this cross was the triploid Cavendish banana strain, a sterile hybrid that is only grown asexually. Recently, the Panama fungus has been observed more frequently parasitizing the Cavendish banana, and scientists claim that this type of banana is on the brink of extinction. Which of the following provides the best explanation of the scientists' claim regarding the threat to the Cavendish banana? A The triploid genome of the Cavendish banana makes it susceptible to the negative impact of recessive alleles. B Having three of each chromosome interferes with normal function of the cells and increases the likelihood of contracting a disease. C The lack of genetic diversity of the Cavendish banana decreases the chance that a variation exists in the population that is immune to the fungus. D Asexual reprodu
C The lack of genetic diversity of the Cavendish banana decreases the chance that a variation exists in the population that is immune to the fungus.
Sea otters Which of the following best describes what happened to the otter population between 1750 and 1850 ? A The population decreased in size as a result of a loss of genetic diversity. B The population decreased in size as a result of habitat loss. C The population lost genetic diversity as a result of a bottleneck effect. D The population lost genetic diversity as a result of the founder effect.
C The population lost genetic diversity as a result of a bottleneck effect
Which of the following observations would provide the strongest evidence that two plants belong to different biological species? A There are variations in their RNARNA sequences. B The leaves and flowers show morphological differences. C They produce viable but sterile offspring. D They occupy unique habitats in an ecosystem.
C They produce viable but sterile offspring.
MRSA is the acronym for methicillin-resistant Staphylococcus aureus. Many of the strains of the common bacterium are also resistant to other antibiotics in use today. The resistance is linked to a collection of genes carried on plasmids that are passed from one bacterium to another by conjugation. Suppose a newly discovered, chemically different antibiotic is used in place of methicillin. Which of the following would be the most likely effect on Staphylococcus aureus antibiotic resistance? A The gene for methicillin resistance, no longer needed, would disappear entirely from Staphylococcus aureus populations within a few generations. B Transmission of the methicillin-resistance plasmid by conjugation would increase among the Staphylococcus aureus population as the genes would confer resistance to the new antibiotic. C Transmission of the methicillin-resistance plasmid would gradually decrease but the plasmid would no
C Transmission of the methicillin-resistance plasmid would gradually decrease but the plasmid would not entirely disappear from the Staphylococcus aureus population.
The TAS2R38 gene encodes a receptor protein that influences the ability to taste bitterness. The gene has two alleles: a dominant, wild-type allele that enables an individual (taster) to taste bitterness and a recessive, mutant allele that interferes with the ability of an individual (nontaster) to taste bitterness. Three single nucleotide mutations in the coding region of the TAS2R38 gene are associated with the nontaster allele. The nucleotides present at the three positions are shown in the table below. In a sample of 2,400 people, 1,482 were found to have the dominant (taster) phenotype. Assuming that the population is in Hardy-Weinberg equilibrium, approximately how many individuals in the sample are expected to be heterozygous for TAS2R38?
C 1,133
A particular gene has two alleles, a dominant allele A� and a recessive allele a�. The frequency of allele A� is 0.550.55. If the population is in Hardy-Weinberg equilibrium with respect to the gene, then what is the expected frequency of genotype Aa��? A 0.203 B 0.303 C 0.405 D 0.495
D 0.495
A scientist is studying a population of lizards with three different color phenotypes. The color phenotype is controlled by a single gene with two alleles: an incompletely dominant allele A� and a recessive allele a�. The scientist collected data on the color of 100100 lizards. The data are shown in the table. PhenotypeGenotypeNumber ObservedRedAA��7575PurpleAa��1515Blueaa��1010 To test the hypothesis that the population is at Hardy-Weinberg equilibrium, the scientist performed a chi-square test. Which of the following values is closest to the chi-square value the scientist calculated? A 0.1 B 1.9 C 18.3 D 23.1
D 23.1
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 Can simple organic molecules form spontaneously in an oxygen-free atmosphere?
Which of the following describes a scenario that would result in the phenotypic change shown in the graph? A A fish that has mouth parts adapted to eat moderately sized prey is introduced into a lake in which there are only large and small prey. B A population of mice live on the ground and in short trees. An invasive, tree-dwelling snake that preys on the mice is introduced into the area. C Climate change-induced warming of arctic tundra reduces average snow cover that lighter-colored arctic foxes rely on for camouflage. Darker-colored arctic foxes are better suited to the exposed moss and grass habitat. D House sparrows that lay smaller-than-average clutches of eggs produce fewer viable offspring, while larger-than-average clutches of eggs result in malnourished chicks that have a higher mortality rate.
D House sparrows that lay smaller-than-average clutches of eggs produce fewer viable offspring, while larger-than-average clutches of eggs result in malnourished chicks that have a higher mortality rate.
Figure 1. For paired groups of organisms, a comparison of the number of amino acid substitutions in cytochrome c� with the time since the groups diverged from a common ancestor Researchers analyzed the amino sequence of the protein cytochrome c� in various groups of organisms and determined the number of amino substitutions that have occurred in the different groups of organisms. They plotted the data with respect to the time since divergence of the members of paired groups from a common ancestor (Figure 1). Based on the data, which of the following organisms are most distantly related? A Birds and mammals B Mammals and reptiles C Fish and land vertebrates D Insects and vertebrates
D Insects and vertebrates
Goats and sheep belong to the same family but different genera. While they often live together in the same pastures, the hybrid offspring that are occasionally produced between the two species rarely survive. When such a hybrid does survive, it is usually sterile. Which of the following best explains the mechanism that maintains reproductive isolation between goats and sheep? A Gene flow is prevented because the two species belong to different trophic levels and therefore do not share a food source. B Habitat isolation creates a prezygotic barrier between the two species. C The males of one species and the females of the other species are fertile at different times. D The two species have a different number of chromosomes, resulting in a postzygotic barrier.
D The two species have a different number of chromosomes, resulting in a postzygotic barrier.
Sugar gliders and Northern flying squirrels are mammals that have many morphological similarities despite being genetically different. Both are nocturnal and have large eyes to help them see in the dark. Both live in trees and have flaps of skin connecting their front and back legs, and when their front and back legs are extended, the flaps allow the animals to glide from one tree branch to another. Sugar gliders are native to Australia, and Northern flying squirrels are native to North America. Which of the following best explains the morphological similarities between these two species? A The similarities in traits indicate the species are the result of divergent evolution from a common ancestor that had the same traits that these two species share. B The traits evolved through sympatric speciation, which often results in species being highly similar because they evolve in the same area. C The two species evolved a
D The similarities between the species evolved independently as a result of similar selective pressures in each species' environment.The similarities between the species evolved independently as a result of similar selective pressures in each species' environment.
