AP Bio


  1. Flashcard #1
    Term: 1. 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?
    Definition: The extinction rate of amphibians in the 21st century compared with the extinction rate of amphibians during the 20th century.

    Flashcard #2
    Term: 2. 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?
    Definition: Courtship rituals specific to each island lizard species prevent the lizards from interbreeding.

    Flashcard #3
    Term: 3. 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?
    Definition: The bacteria are able to recognize and destroy the antibiotics by breaking them down extracellularly.

    Flashcard #4
    Term: 4. 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?
    Definition: Longer beaks increase the fitness of the birds in wild habitats.

    Flashcard #5
    Term: 5. 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 and b=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 and b=0.4. Which of the following could best explain the increase in the frequency of the B allele in the population after five years?
    Definition: The frequency of the B allele increased because squirrels with gray fur exhibited greater fitness.

    Flashcard #6
    Term: 6. 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?
    Definition: 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.

    Flashcard #7
    Term: 7. Paleoclimatic analysis has generated a claim that there is a possible correlation between an extinction event around 29 million years ago that allowed grasslands to become abundant and the adaptive radiation of several groups of butterflies. Which of the following proposes the best alternative hypothesis for the claim?
    Definition: There is a correlation between the rapid and wide-ranging decrease in species richness of insects in general 29 million years ago and the increase in species richness and diversity among the butterfly population during the same time period.

    Flashcard #8
    Term: 8. Researchers observed selected internal structures of four different microscopic organisms as part of a larger study on the divergence between eukaryotes and prokaryotes. Their observations are recorded in Figure 1. Which organism would the researchers most likely predict to be the most distantly related to eukaryotes?
    Definition: Organism III.

    Flashcard #9
    Term: 9. In humans, one allele of the APOE gene, called APOE–ε2, 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–ε2 allele. Which of the following states a valid null hypothesis about the future distribution of APOE alleles in future generations in the United States?
    Definition: As high cholesterol diets become more common in the United States, individuals with the APOE–ε2 allele will have a better survival rate from heart disease than those without the allele, so the allele will increase in frequency.

    Flashcard #10
    Term: 10. Students analyzed several photosynthetic eukaryotic organisms in the laboratory to determine their phylogenetic relationships. The organisms were Spirogyra (a green alga), a moss, a spruce tree, and an apple tree. Which of the following rows of data listed in table 1 best supports the possibility of a common ancestor for the organisms listed there?
    Definition: Cell wall composed of cellulose.

    Flashcard #11
    Term: 11. Two species of fish that live in extremely cold environments produce near-identical antifreeze glycoproteins, called AFGPs. Scientists have determined the origins of the AFGP gene in both species. Based on the information in Table 1, which of the following statements best describes the production of nearly identical AFGPs in these two species of fish?
    Definition: The Antarctic fish species evolved into a separate species after being geographically isolated from the Arctic population because of commercial fishing.

    Flashcard #12
    Term: 12. 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. 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?
    Definition: Since the E and Z strains are found in the same geographic area, they will hybridize, leading to a single strain that produces the dominant form of 11−TDA.

    Flashcard #13
    Term: 13. 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?
    Definition: After the dinosaur extinction, many ecological niches became available, leading to the adaptive radiation of mammals.

    Flashcard #14
    Term: 14. African elephants, Loxodonta africana, are often hunted illegally for their tusks. Both male and female elephants have tusks, although the tusks are much larger in the males. Researchers have followed the elephant population in Gorongosa National Park in Mozambique for many years. 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 ?
    Definition: Tusklessness in female elephants is a dominant trait.

    Flashcard #15
    Term: 15. Researchers studying the evolutionary relationships of three species of snails collected the data shown in Table 1. Which of the following data sets is most likely to provide reliable information about the evolutionary relationships among these three snail species?
    Definition: Location of fossils and shell orientation.

    Flashcard #16
    Term: 16. A scientist is attempting to provide support for the hypothesis that RNA was the first genetic material. Which of the following would be a workable alternate hypothesis?
    Definition: RNA exists in both single-stranded and double-stranded configurations; however, it is less stable compared with DNA.

    Flashcard #17
    Term: 17. Scientists investigated the role that beak depth plays in the ability of one species of seed-eating finch to reproduce. The scientists calculated the average beak depth of finches in mating pairs and then observed whether or not the pairs produced at least one offspring that survived to the next season. Based on the data in Figure 1, which of the following best describes the concept illustrated?
    Definition: Increasing average beak depth results in increasing finch fitness.

    Flashcard #18
    Term: 18. Researchers examined the ability of cultures of the bacterium Pseudomonas aeruginosa to adapt to the antibiotics ceftazidime and avibactam when they are administered together. Which of the following experiments would specifically determine which gene is responsible for ceftazidime-avibactam sensitivity in P. aeruginosa ?
    Definition: Perform gene knockout (targeted mutation) of either the hmgA, 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.

    Flashcard #19
    Term: 19. Over many years of a breeding program, a zoo has an established population of foxes that is well adapted for living in captivity. A representative sample of wild foxes from the neighboring forest was used to start the zoo population. The behaviors of equal numbers of foxes from each population were assessed. The phenotypic variation in behavior between the two populations can best be described as resulting from
    Definition: sexual selection.

    Flashcard #20
    Term: 20. Finch beak depth was measured before and after a severe drought in 1977. Using the evidence provided, which of the following best justifies the researchers' claim?
    Definition: Finch beak depth increased after the drought due to intraspecific competition since finches with deeper beaks attract more mates.

    Flashcard #21
    Term: 21. Gaucher disease type 1 (GD1) is a recessive genetic disease that affects 1 in 900 individuals in a particular population. Assuming the population is in Hardy-Weinberg equilibrium, calculate the frequency of the wild-type (nonmutant) allele for the enzyme glucocerebrosidase.
    Definition: 0.967.

    Flashcard #22
    Term: 22. 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)?
    Definition: Without migration or mutation, new alleles cannot be introduced to the population.

    Flashcard #23
    Term: 23. 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?
    Definition: Organic waste sinking to the ocean floor would have used the unique hot water environment as an energy source to begin manufacturing food.

    Flashcard #24
    Term: 24. In a large, isolated population of an insect species, a specific gene locus has one dominant allele (A) and one recessive allele (a). Which of the following could best account for the change in genotypic frequencies over the ten generations?
    Definition: The population is not exhibiting random mating between individuals.

    Flashcard #25
    Term: 25. In a long‑term study of a population of gray squirrels, researchers observed that most of the squirrels had gray fur. However, there were some individuals in the population with white fur (albino). Over a ten-year period, the average frequency of albino squirrels in the population was 0.18. If the population is assumed to be in Hardy-Weinberg equilibrium, the average frequency of the dominant allele is closest to which of the following?
    Definition: 0.50.

    Flashcard #26
    Term: 26. Many scientists claim that the synthesis of the first organic molecules from inorganic precursors was possible because of the highly reducing atmosphere found on primitive Earth. Which of the following is an appropriate null hypothesis that could be used when investigating the claim?
    Definition: Organic molecules were transported to primitive Earth by a meteorite or other celestial event.

    Flashcard #27
    Term: 27. Low doses of antibiotics are often added to livestock feed to increase production. Which of the following best represents the next step the researchers should take with respect to experimental design?
    Definition: Group 1: high dose of streptomycin + low dose of additional antibiotic; Group 2: low dose of streptomycin + high dose of additional antibiotic.

    Flashcard #28
    Term: 28. Hemoglobin is a highly conserved protein used by all mammals to transport oxygen. Which of the following best describes the importance of the number of amino acid differences indicated in Table 1?
    Definition: They reflect random changes due to translation errors.

    Flashcard #29
    Term: 29. Scientists want to determine whether the rapid economic growth in China between 1950 and 2000 caused a mass extinction of animal species during that time period. Which of the following is the null hypothesis most relevant for evaluating the data in Table 1 ?
    Definition: There is a significant difference between the extinction rate for mammals in China and the background extinction rate for mammals.

    Flashcard #30
    Term: 30. Researchers were modeling the effects of repeated cycles of isolation with occasional interbreeding among five hypothetical fish species (species A, B, C, D, and E) found in two separate lakes (lakes I and II). Which of the following mechanisms could most likely account for the origin of species B in Lake I?
    Definition: Stabilizing selection.

    Flashcard #31
    Term: 31. Which of the following data could best support the claim that species B arose from a speciation event in Lake I?
    Definition: Species A and species B have similar body shapes due to convergent evolution in their habitats.

    Flashcard #32
    Term: 32. Humans vary in their ability to taste the bitter chemical compound phenylthiocarbamide (PTC). Assuming the population is in Hardy-Weinberg equilibrium, what is the frequency of the non-taster allele?
    Definition: 0.41.

    Flashcard #33
    Term: 33. Figure 1 compares two models of speciation, A and B. Which of the following best explains how the ecological conditions are likely to be different in the two models?
    Definition: In model A the ecological conditions are changing drastically from generation to generation; in model B the ecological conditions remain unchanged.

    Flashcard #34
    Term: 34. Rock pocket mice live in the deserts of the American southwest. 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?
    Definition: Light-colored mice are significantly more susceptible to predation by owls in habitats with lava rocks than in habitats with sandy soil.

    Flashcard #35
    Term: 35. Students observed the distribution of different color phenotypes in northern ravine salamanders (Plethodon electromorphus) before and after a spring flood. Which of the following is an appropriate null hypothesis regarding the phenotypic frequencies of this population of salamanders before and after the flood?
    Definition: More dark-brown salamanders migrated to a new, drier area because of the flood and fewer of them remained in the original habitat.

    Flashcard #36
    Term: 36. Staphylococcus aureus is a pathogenic bacterium that can infect a wide range of host species, including humans. Which of the following processes is most consistent with the differences in the amino acid sequences listed in Table 1 ?
    Definition: Each strain is best adapted to a specific host species.

    Flashcard #37
    Term: 37. 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?
    Definition: Sequence the genes of different S. aureus strains and construct a cladogram representing their relatedness.

    Flashcard #38
    Term: 38. Table 1 shows a trend of increasing milk yield for cows. Based on the information provided, which of the following best describes the source of the rapid increase in milk production from 1976 to 2015 ?
    Definition: Starting in the 1970s, farmers increased the selective breeding of cows and bulls for offspring that produced more milk.

    Flashcard #39
    Term: 39. Figure 1 illustrates a process that occurs in a certain group of organisms. Which of the following best predicts the importance of this process?
    Definition: This process is common to all members of Eukarya and allows noncoding regions of RNA to be removed so that proteins with the correct amino acid sequence are produced.

    Flashcard #40
    Term: 40. Climate change is disrupting the length of winter in various ecosystems, resulting in less snowfall and milder winters. Which of the following best explains why the brown-feathered phenotype in tawny owls has increased over the past 28 years?
    Definition: Darker feather color in tawny owls makes them less visible to predators as they sit in the trees.

    Flashcard #41
    Term: 41. 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?
    Definition: Surviving the bottleneck event will be random, so any change in the allelic frequencies of the salamander population is not attributed to fitness.

    Flashcard #42
    Term: 42. Transposable elements are significant features in the genomes of almost all eukaryotic organisms. Which of the following best predicts how phylogenetic relationships might be revised if transposon 1 was not found in chimpanzees?
    Definition: Chimpanzees would be more closely related to humans than to bonobos