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AP Biology -- John Burroughs School -- M. Bahe Some Practice For Evolution & The Origin of Life 16-20from the REAL 2014, 2013 and 2012 AP Bio Exams) (These Questions question come Questions 16-20 The three-spined stickleback (Gasterosteus aculeatus) isaculeatus) a small fishisfound infish bothfound marine and freshwater The three-spined stickleback (Gasterosteus a small in both marine and freshwater The three-spined stickleback (Gasterosteus aculeatus) isofaindividuals small found inwith botharmor-like marine andcovering freshwater environments. MarineMarine stickleback populations consist mainlymainly with armor-like plates most most environments. stickleback populations consist of fish individuals plates covering of their body surface (completely plated). Approximately 10,000 years ago, some marine sticklebacks colonized environments. Marine stickleback populations consist mainly of individuals with armor-like plates covering most of their body surface (completely plated). Approximately 10,000 years ago, some marine sticklebacks colonized freshwater After many plated). generations in the freshwater environments, themarine freshwater stickleback of freshwater theirenvironments. body surface (completely Approximately 10,000 years ago, some sticklebacks colonized environments. After(low many generations in the freshwater environments, the freshwater stickleback populations lacked the armor plating plated) typical of freshwater marine stickleback populations. freshwater environments. After many generations in the environments, the freshwater stickleback populations lacked the armor plating (low plated) typical of marine stickleback populations. populations lacked the armor plating (low plated) typical of marine stickleback populations. Over the period between 1957 and 2005, one freshwater population, in Lake Washington, a lake in a coastal Over the period between 1957 and 2005, from one freshwater population, in Lake Washington, a lake in a coastal region of the northwestern United States, changed having a majority of individuals of the low-plated Overtothe between 1957 and 2005, one freshwater population, in Lakeofthe Washington, a lake in a coastalphenotyp region of period the northwestern United changed from having a majority individuals of the low-plated phenotype having more individuals of States, the completely-plated phenotype than of low-plated phenotype. region of the northwestern United States, changed from having a majority of individuals of the low-plated phenotype Figure 1toshows distribution of plated phenotypes in Lake Washington at fourphenotype. time pointsFigure havingthe more individuals of the completely-plated phenotype thansticklebacks of the low-plated 1 shows th to distribution having more2005. individuals of the completely-plated phenotype than of the low-plated phenotype. Figure 1 shows between 1957 and of plated phenotypes in Lake Washington sticklebacks at four time points between 1957 and 2005.the distribution of plated phenotypes in Lake Washington sticklebacks at four time points between 1957 and 2005. A single gene, ectodysplasin (EDA), is thought to be responsible for the variation in the number of armor plates in A single gene, ectodysplasin (EDA), isconstructed thought to responsible be the variation in of armor plates sticklebacks. Figure 2 shows a phylogenetic tree byresponsible comparing DNA sequences of the the number EDAofgene from A single gene, ectodysplasin (EDA), is thought to be for for the variation in the number armor plates in i sticklebacks. Figure 2 shows a phylogenetic tree constructed by comparing DNA sequences of the EDA gene from a number of stickleback populations with low-plated or completely plated phenotypes. Figure 3 shows a sticklebacks. Figure 2 shows a phylogenetic tree constructed by comparing DNA sequences of the EDA gene from a a number of stickleback populations with or plated phenotypes. Figure 3from shows a phylogenetic phylogenetic tree constructed by comparing thelow-plated sequences of completely 25 genesplated that were randomly selected number of stickleback populations with low-plated or completely phenotypes. Figure 3 shows athe phylogenetic same populations as shown in Figure 2. Insequences both figures, shaded populations display the completely plated tree constructed by comparing the of 25 genes that were randomly selected from the same populations tree constructed by comparing the sequences of 25 genes that were randomly selected from the same populations as as phenotype. shown in Figure 2. In both figures, shaded populations display the completely plated phenotype. shown in Figure 2. In both figures, shaded populations display the completely plated phenotype. Unauthorized copying or reuse Unauthorized copying or reuse of of of this page is illegal. anyany partpart of this page is illegal. THE NEXT PAGE. GOGO ONON TOTO THE NEXT PAGE. AP Biology -- John Burroughs School -- M. Bahe You need the information on the previous page for these 4 questions. 1. Which of the following best explains the differences in the armor of the Lake Washington stickleback population summarized in Figure 1 ? a. ! Analysis of somatic cells using chromosomal staining and light microscopy indicates that stickleback fish have a diploid number!of 42. ! b. Stickleback males from natural freshwater populations are typically more aggressive when competing for mates than are stickleback males from laboratory-bred populations. ! c. Fish exhibiting the low-plated phenotype were selected against in the Lake Washington stickleback population over the last 50 years. ! d. Migration of individuals from other freshwater environments to Lake Washington led to gene flow between populations that were once geographically isolated. 2. A completely-plated stickleback from a marine population was mated to a low-plated stickleback from a freshwater population. The resulting F1 hybrids all displayed a completely plated phenotype. When the F1 hybrids were allowed to interbreed, the resulting F2 generation included completely plated offspring and low-plated offspring in an approximate 3:1 ratio. Which of the following conclusions is best supported by the results of the breeding experiments? ! a. Phenotypic variation in the F2 generation suggests that armor morphology is controlled by many alleles of a single gene. ! b. The completely-plated phenotype is controlled by a dominant allele of a single gene. ! c. Armor loss is an acquired characteristic that is affected by one or more environmental factors. ! d. Patterns of armor plating in stickleback populations are regulated by sex-specific signals. 3. Prior to 1960, Lake Washington was highly polluted and underwater visibility was limited to one or two meters. In the late 1960s, a large cleanup effort reduced pollution, resulting in visibility that increased to six to seven meters by 1976. Which of the following best explains how the change in underwater visibility affected armor plating in Lake Washington sticklebacks between 1957 and 1976 ? a. Higher visibility allowed sticklebacks to increase their food consumption to make armor production easier. b. Higher visibility made the sticklebacks more susceptible to large-toothed predators in the lakes, giving complete armor a selective advantage. c. Clearer water allowed sunlight to penetrate to deeper depths, so the sticklebacks had to increase the amount of armor to protect themselves from the resulting increase in water temperature. d. Clearer water contained fewer of the molecular building blocks needed for armor production, so sticklebacks showed a reduction in the amount of armor. 4. Evolution of a new trait typically takes many generations. Yet a dramatic shift in the extent of armor plating in the Lake Washington stickleback population occurred in the 50 years following the cleanup of the lake. Which of the following best describes the mechanism of the rapid evolution of the armor phenotype in the Lake Washington sticklebacks? a. Pollutants in Lake Washington forced the sticklebacks to increase their mutation rate. b. The rapid change in the Lake Washington ecosystem required individual sticklebacks to evolve complete armor quickly. c. The increase in visibility in Lake Washington allowed sticklebacks to visually select mates with low armor. d. New selective pressures favored individuals with the plated phenotype, causing the plated allele frequency in the population to quickly increase. 5. The pesticide DDT was widely used in the 1940s as a method of insect control. In the late 1950s the first DDTresistant mosquitoes were discovered, and eventually DDT-resistant mosquitoes were found globally. When DDT is used now, the development of DDT resistance in mosquito populations occurs in months rather than years. Which of the following best explains the observations concerning DDT resistance in mosquitoes? a. Competition for limited resources causes mosquitoes to migrate to geographical areas that have richer supplies of DDT. b. The proportion of DDT-resistant mosquitoes in a population remains constant due to the metabolic costs of DDT utilization. c. Natural selection favors DDT-resistant mosquitoes that are already present in a population when DDT exposure occurs. d. DDT is a chemical signal that delays normal reproductive cycles in many mosquito populations. AP Biology -- John Burroughs School -- M. Bahe 6. Methicillin-resistant Staphylococcus aureus (MRSA) can be a serious threat to human health. There is evidence that S. aureus infections are common in hospitals and that MRSA have become resistant to other antibiotics besides methicillin. This suggests that the rapid evolution of resistance in the bacteria poses a serious publichealth challenge. Which of the following best explains the ability of MRSA to evade existing drug therapies? a. MRSA have very long generation times and very large population sizes. b. MRSA develop new alleles by intentionally introducing specific mutations that will give them a selective advantage over other bacteria. c. MRSA metabolize many drugs in their lysosomes and therefore evolve resistance at a high rate. d. MRSA exchange genetic material with other antibiotic-resistant bacteria, which can spread resistance in the S. aureus population. 7. Undersea landslides can disrupt marine habitats by burying organisms that live on the ocean floor. The graph at right shows the size of a population of a certain organism that lives on the ocean floor. The population was affected by a recent landslide at the time indicated on the graph. Which of the following best predicts how the population will be affected by the landslide? a. The surviving organisms will evolve into a new species. b. The reduced population will likely have allelic frequencies that are different from the initial population. ! c. The population will adapt to deeper waters to avoid future landslides. ! d. The reduced population will have a greater number of different genes than the initial population. 8. Data regarding the presence (+) or absence (-) of five derived traits in several different species are shown in the table below. Which of the following cladograms provides the simplest and most accurate representation of the data in the table? AP Biology -- John Burroughs School -- M. Bahe You will need this information for the next 3 Questions. 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. 9. The divergence between the two populations of Rhagoletis must have occurred very rapidly because a. the apple tree was imported into North America with European settlement approximately 200 years ago b. flies were imported into North America with European settlement approximately!200 years ago c. long-distance rail transport of fruit increased only after the American Civil War (1861–1865) d. heavy use of gunpowder during the American Civil War (1861–1865) led to increased mutation rates in many natural populations of plants and animals 10. 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 11. Matings between individuals from the!two populations of Rhagoletis produce hybrid flies that appear to be healthy and have normal life spans. The eggs laid by these hybrid flies, however, hatch less often than those of flies from either of the two populations. What isolating mechanism seems to be important in this hybrid population? a. !Prezygotic isolation! b. Mechanical isolation c. Reduced hybrid fertility d. Habitat isolation 12. A group of mice was released into a large field to which no other mice had access. Immediately after the release, a representative sample of the mice was captured, and the fur color of each individual in the sample was observed and recorded. The mice were then returned to the field. After twenty years, another representative sample of the mice was captured, and the fur color of each individual in the sample was again recorded. Which of the following best explains the change in the frequency distribution of fur color phenotypes in the mouse population, as shown in the figures above? a. The allele for gray fur color is unstable, and over twenty years most of those alleles mutated to become alleles for black fur. b. The field was composed primarily 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 hardest to capture and so were underrepresented in the twenty-year sample. AP Biology -- John Burroughs School -- M. Bahe 13. Scientists have found that the existing populations of a certain species of amphibian are small in number, lacking in genetic diversity, and separated from each other by wide areas of dry land. Which of the following human actions is most likely to improve the long-term survival of the amphibians? a. Cloning the largest individuals to counteract the effects of aggressive predation b. Reducing the population size by one-fifth to decrease competition for limited resources c. Constructing a dam and irrigation system to control flooding d. Building ponds in the areas of dry land to promote interbreeding between the separated populations 14. To determine the evolutionary history and relationships among organisms, scientists gather evidence from a wide variety of sources including paleontology, embryology, morphology, behavior, and molecular biology. A phylogenetic tree of vertebrates is shown. Which of the following statements is most consistent with the phylogenetic tree shown? a. Birds and turtles evolved their own means of gas exchange independently of the other vertebrates. b. Mammals are most closely related to birds because they share a direct common ancestor.! c. The common ancestor of reptiles, birds, and mammals produced amniotic eggs.! d. Crocodiles are direct descendents of ray-finned fishes since they live in the same environment. 15. Ellis-van Creveld syndrome is a recessive genetic disorder that includes the characteristics of short stature and extra fingers or toes. In the general population, this syndrome occurs in approximately 1 in 150,000 live births. In a particular isolated population, however, the incidence of this syndrome among live births! is 1 in 500. Assume that both the isolated population and!the general population are in Hardy-Weinberg equilibrium with respect to this syndrome. Which of the following best describes the difference between the frequency of the allele that causes the syndrome in the general population and the frequency of the allele in the isolated population? a. The frequency of the Ellis-van Creveld allele is 0.002 in the isolated population and 0.0000066 in the general population,!which suggests that selection for this trait is occurring in both populations. b. The frequency of the Ellis-van Creveld allele is 0.0447 in the isolated population and 0.0026 in the general population, showing that the rate of genetic mutation is highest among individuals in the isolated population. c. The frequency of the Ellis-van Creveld allele is 0.002 in the isolated population and 0.0000066 in the general population, which demonstrates gametic incompatibility between the populations. d. The frequency of the Ellis-van Creveld allele is 0.0447 in the isolated population and 0.0026 in the general population, which suggests that genetic drift has occurred in the isolated population. 16. 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. AP Biology -- John Burroughs School -- M. Bahe For the Next 4 questions: 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. 17. 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. 18. 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. 19. 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. 20. 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? a. A loss of food supply for the finches! b. The end of the drought! c. An increase in drought conditions! d. An increase in predators consuming finches 21. Five new species of bacteria were discovered in Antarctic ice core samples. The nucleotide (base) sequences of rRNA subunits were determined for the new species. The table below shows the number of nucleotide differences between the species. Which of the following phylogenetic trees is most consistent with the data? AP Biology -- John Burroughs School -- M. Bahe 22. 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. 23. A group of students summarized information on five great extinction events in the table above. The students are sampling a site in search of fossils from the Devonian period. Based on the chart, which of the following would be the most reasonable plan for the students to follow? a. Searching horizontal rock layers in any class of rock and try to find those that contain the greatest number of fossils b. Collecting fossils from rock layers deposited prior to the Permian period that contain some early vertebrate bones c. Looking in sedimentary layers next to bodies of water in order to find marine fossils of bivalves and trilobites d. Using relative dating techniques to determine the geological ages of the fossils found so they can calculate the rate of speciation of early organisms AP Biology -- John Burroughs School -- M. Bahe 24. CALCULATION PROBLEM: Researchers observe a large population of birds on a remote island. Birds in the population are found to have either red crest feathers or white crest feathers on their heads. Genetic analysis indicates that the allele for red crest feathers is dominant over the allele for white crest feathers. In a survey of the population, the researchers determine the frequencies of the crest-feather phenotypes. The results of the survey are shown in the table below. Frequencies of Phenotypes in an isolated Bird Population Phenotype Number of Individuals Red Crested Feathers 11,088 White Crested Feathers 1,759 Assuming that the bird population is in Hardy- Weinberg equilibrium, what proportion of future populations is expected to be heterozygous for the allele controlling crest feather color? Give your answer as a value between 0 and 1, rounded to two decimal places. 25. CALCULATION PROBLEM: Some people have the ability to taste a bitter chemical called phenylthiocarbamide (PTC). The ability to taste PTC is due to the presence of at least one dominant allele for the PTC taste gene. The incidence of nontasters in North America is approximately 45%. Assuming the population is in Hardy-Weinberg equilibrium, what percent of the North American population is homozygous dominant for the ability to taste PTC? Provide your answer as a number between 0 and 1 to the nearest hundredth. 26. CALCULATION PROBLEM: In a population of certain frogs in which the allele for brown skin is dominant to the allele for green skin, a drought leads to selection against green-skinned frogs. When the drought ends,!12 percent of the remaining frogs exhibit the green-skin phenotype. If the population is now in HardyWeinberg equilibrium, what will be the frequency of the green-skin allele in the next generation? Provide your answer to the nearest hundredth. AP Biology -- John Burroughs School -- M. Bahe The remaining questions are short answer (paragraph) answers. Write the answers on a separate sheet of paper. 27. In a study of bacterial communities, researchers investigated interactions among naturally occurring strains of Vibrio bacteria. The researchers found that some Vibrio bacteria secrete antimicrobial substances that inhibit the growth and reproduction of other bacteria (antagonism). The researchers also found that some strains of Vibrio bacteria produce no antimicrobial substances themselves but instead live in close proximity to other bacteria that produce antimicrobial substances to which they are not susceptible (cooperation). By testing approximately 35,000 pairs of naturally occurring strains of Vibrio bacteria, the researchers identified 830 antagonistic interactions among genetically related Vibrio strains. The graph represents the probability of antagonism between any two given strains of Vibrio bacteria as a function of genetic relatedness (genetic distance). The greater the genetic distance, the less related are any two bacterial strains. a. Describe ONE type of molecular evidence that can be used to determine the genetic relatedness of 6. Innaturally a study of bacterialpopulations. communities, researchers investigated interactions among natur bacterial strains isolated from occurring Vibrio bacteria. The researchers found that between some Vibrio bacteria and secrete antimicrobial b. Using the information presented in the graph, describe the relationship antagonism genetic growth and reproduction of other bacteria (antagonism). The researchers also found th relatedness in the communities of Vibrio bacteria sampled for the study. bacteria produce no antimicrobial substances themselves but instead live in close prox c. Provide reasoning to show how the results of the study support the claim that cooperation among Vibrio bacteria can increase the fitness of some individual bacteria living in a natural environment. produce antimicrobial substances to which they are not susceptible (cooperation). Byare testing approximately 35,000 of naturally occurring strains 28. Fossils of lobe-finned fishes, which ancestors of amphibians, arepairs found in rocks that are at least 380of Vibrio bacteria 830 antagonistic interactions among genetically Vibrio strains. The graph repr million years old. Fossils of the oldest amphibian-like vertebrate animals with truerelated legs and lungs are found antagonism between in rocks that are approximately 363 million years old. any two given strains of Vibrio bacteria as a function of genetic r Three samples of rocks are available that might fossils of a transitional between distance). The contain greater the genetic distance, thespecies less related are lobe-finned any two bacterial strain fishes and amphibians: one rock sample that is 350 million years old, one that is 370 million years old, and one that is 390 million years old. (a) Describe ONE type of molecular evidence that can be used to determine the gene strains isolated from to naturally occurring populations. a. Select the most appropriate sample of rocks in which search for a transitional species between lobefinned fishes and amphibians. Justify your selection. (b) Using the information in the graph,that describe relationship between a b. Describe TWO pieces of evidence provided by fossils ofpresented a transitional species wouldthe support a relatedness in the communities of Vibrio bacteria sampled for the study. hypothesis that amphibians evolved from lobe-finned fishes. (c) Provide reasoning to show how the results of the study support the claim that coo 29. In fruit flies (Drosophila melanogaster), straight wing shape is dominant to curly wing shape. A particular bacteria can increase the fitness of some individual bacteria living in a natural env population of fruit flies is in Hardy-Weinberg equilibrium with respect to the alleles for wing shape. The Hardy-Weinberg equation, given below, is useful in understanding population genetics: 2 PAGE FOR ANSWERING 6 p2 +2pq+qQUESTION =1 a. b. 2 2 Explain what the terms ( p , 2pq, and q ) represent in the population of fruit flies. Describe one condition that is necessary for the population to be in equilibrium. 30. Populations of a plant species have been found growing in the mountains at altitudes above 2,500 meters. Populations of a plant that appears similar, with slight differences, have been found in the same mountains at altitudes below 2,300 meters. a. Describe TWO kinds of data that could be collected to provide a direct answer to the question, do the populations growing above 2,500 meters and the populations growing below 2,300 meters represent a single species? b. Explain how the data you suggested in part (a) would provide a direct answer to the question. 31. Fossils of a microscopic organism are found in rocks determined to be over 3.5 billion years old. Identify TWO types of evidence that would help answer the question of whether the organism was photosynthetic. Amino Acid 104 Arginine (Arg) Lysine (Lys) Arginine (Arg) Arginine (Arg) Figure 2. Codon Table -18- GO ON TO THE NEXT PAGE. Figure 1. Student-constructed Phylogenetic Tree of Vertebrate Species with Incorrect Placement of “Lys” A student constructed the phylogenetic tree shown in Figure 1 by comparing the amino acid sequences of -hemoglobin in the four species. The student placed “Lys” at an incorrect position on the phylogenetic tree in an attempt to show when the mutation affecting amino acid 104 occurred. -hemoglobin is a highly conserved protein among vertebrates. The identity of amino acid 104–one of the variable amino acids in the polypeptide–in four vertebrate species is shown in the table above. Unauthorized copying or reuse of any part of this page is illegal. 3. Species Horse Gorilla Chimpanzee Human AMINO ACID AT POSITION 104 OF -HEMOGLOBIN Unauthorized copying or reuse of any part of this page is illegal. PAGE FOR ANSWERING QUESTION 3 -19- GO ON TO THE NEXT PAGE. (b) Predict the most likely single mutation affecting amino acid 104 in the species and justify how -hemoglobin can function normally in all four species despite the mutation. (a) Refine the student’s model by placing “Lys” at the correct position on the phylogenetic tree to indicate where the Arg-to-Lys mutation most likely occurred. Provide ONE piece of reasoning to support your placement of “Lys” on the phylogenetic tree. AP Biology -- John Burroughs School -- M. Bahe Question #32