pda natrual selection

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. B Sexual selection for females without tusks between 1977 and 1992. C Tusklessness in female elephants is a dominant trait that is only expressed in females. D After 1992, female elephants from neighboring populations merged, with the population in the park adding more tuskless individuals to the population.

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. B Parental pairs with a specific beak depth ate the most nutritious seeds. C Finches with a certain beak depth rarely find mates. D Increasing average beak depth results in increasing finch fitness.

A Parental pairs with a specific beak depth had the highest reproductive fitness.

Two species of fish that live in extremely cold environments produce near-identical antifreeze glycoproteins, called AFGPsAFGPs. Scientists have determined the origins of the AFGPAFGP gene in both species. Selected characteristics of the two fish species are provided in Table 1. Based on the information in Table 1, which of the following statements best describes the production of nearly identical AFGPsAFGPs in these two species of fish? A The fish eat the same type of food, which resulted in the evolution of similar digestive proteins. B The fish live in environments with similar selective pressures, and those that produce AFGPsAFGPs are better able to survive. C The Antarctic fish species evolved into a separate species after being geographically isolated from the Arctic population because of commercial fishing. D The production of similar AFGPsAFGPs was due to random splicing of exons in both species.

B The fish live in environments with similar selective pressures, and those that produce AFGPsAFGPs are better able to survive.

The phenotypic variation in behavior between the two populations can best be described as resulting from A sexual selection B natural selection C artificial selection D genetic drift

B natrual

Possosing a single copy of the HbS allele has been shown to provide some resistance to infection by Plasmodium falciparum, the parasite that causes malaria. Which of the following individuals represented in the pedigree would have the greatest selective advantage in an area where malaria is common?

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Climate change is disrupting the length of winter in various ecosystems, resulting in less snowfall and milder winters. Scientists in Finland have been observing the tawny owl, a fairly large owl species that is commonly found in woodlands across much of Europe and Asia. Typically, the feathers of the upper body are either brown (BBBB) or gray (bbbb). Scientists studying tawny owls in Finland have found that the percentage of tawny owls that have brown feathers has increased over the past 28 years. 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 processes is most consistent with the differences in the amino acid sequences listed in Table 1 ? A Each host transcribes and translates this gene differently. B S. aureus develops a mutualistic relationship with each host species. C Changes in amino acid sequence are unrelated to protein function. D Each strain is best adapted to a specific host species.

Each strain is best adapted to a specific host species.

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.

Longer beaks allow the birds to better access seeds in bird feeders.

Based on the information provided, which of the following best describes the source of the rapid increase in milk production from 1976 to 2015 ? A From the 1970s to the early 2000s, dairy cows were not used for beef production. B Starting in the 1970s, farmers increased the selective breeding of cows and bulls for offspring that produced more milk. C Reproduction rates in cows and bulls increased significantly in the 1970s. D Cows were healthier after the 1970s, so they lived longer and produced more milk during their lifetime.

Starting in the 1970s, farmers increased the selective breeding of cows and bulls for offspring that produced more milk.

American Tree Sparrows are common in areas that sometimes experience extreme temperature changes. The graph illustrates the body mass distributions of an American Tree Sparrow population before and after a snowstorm. Which of the following statements best describes the change in the tree sparrow population? A The average body weight of the American Tree Sparrow decreased after the snowstorm. The snowstorm did not change the total number of individuals in the population. The average body weight of the American Tree Sparrow increased after the snowstorm The snowstorm had no effect on the average body weight of the Tree Sparrow.

The average body weight of the American Tree Sparrow increased after the snowstorm

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.

The bacteria have high genetic variability and high reproductive rates.

Which of the following includes the most likely change in the coloration of the beetle population after pollution and a correct rationale for the change? The coloration range shifted toward more light-colored beetles, as in diagram 1. The pollution helped the predators find the darkened tree trunks. b.The coloration in the population split into two extremes, as in diagram I1. Both the lighter-colored and the darker-colored beetles were able to hide on the darker tree trunks. The coloration range became narrower, as in diagram Ill. The predators elected beetles at the color extremes. The coloration in the population shifted toward more darker-colored beetle, as in diagram IV. The lighter-colored beetles were found more easily by the predators than were the darker-colored beetles,

The coloration in the population shifted toward more darker-colored beetle, as in diagram IV. The lighter-colored beetles were found more easily by the predators than were the darker-colored beetles,

. 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? The allele for gray fur color is unstable, and over twenty years most of those alleles mutated to become alleles for black fur The field was composed primarily of light-colored soil and little vegetation, affording gray mice protection from predators. Sexual election led to increaped mating frequency of black and brown versus gray and brown The gray mice were hardest to capture and so were underrepresented in the twenty-year sample.

The field was composed primarily of light-colored soil and little vegetation, affording gray mice protection from predators.