AP BIO UNIT 7 TEST QUESTIONS AND
ANSWERS
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? - Correct Answers -The field was primarily composed of light-
colored soil and little vegetation, affording gray mice protection from predators.
A species of snail lives in the intertidal zone along the coast of New England. The dark-
colored variety of the species is more common in northern New England, the light-
colored variety is more common two hundred miles away in southern New England, and
both varieties are commonly found together in central New England. Which of the
following best explains the observed distribution pattern of the snails? - Correct
Answers -Dark-colored snails absorb more solar energy and so survive more readily in
the colder northern waters.
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? - Correct Answers -The isolation prevents gene flow; thus,
the lizards on different islands experience prezygotic isolation.
A moth's color is controlled by two alleles, G and g, at a single locus. G (gray) is
dominant to g (white). A large population of moths was studied, and the frequency of the
G allele in the population over time was documented, as shown in the figure below. In
1980 a random sample of 2,000 pupae was collected and moths were allowed to
emerge.
Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what
percentage of moths in the natural population was white in 1962 ? - Correct Answers -
4%
, For following group of questions first study the description of the situation and then
choose the one best answer to each question following it and fill in the corresponding
oval on the answer sheet.
A survey reveals that 25 percent of a population of 1,000 individuals have attached
earlobes (are homozygous recessivefor the trait). For the following questions, assume
that the population fits the parameters of the Hardy-Weinberg law.
If p equals the frequency of the dominant allele and q equals the frequency of the
recessive allele, which of the following terms represents the frequency of the individuals
who show the dominant phenotype? - Correct Answers -p2 + 2pq
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? - Correct Answers -Finches with bigger
beaks are better able to crack thick-walled seeds and produce more surviving offspring.
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? -
Correct Answers -Longer beaks allow the birds to better access seeds in bird feeders.
Which of the following pieces of evidence best supports the hypothesis that birds and
crocodilians (crocodiles and alligators) are more closely related to each other than they
are to other organisms? - Correct Answers -The skulls of birds and crocodilians have an
opening that is absent in the skulls of other reptiles.
Competition for food would probably be most severe between two - Correct Answers -
closely related species in similar niches
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? - Correct Answers -The similarities between the species evolved
independently as a result of similar selective pressures in each species' environment.
ANSWERS
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? - Correct Answers -The field was primarily composed of light-
colored soil and little vegetation, affording gray mice protection from predators.
A species of snail lives in the intertidal zone along the coast of New England. The dark-
colored variety of the species is more common in northern New England, the light-
colored variety is more common two hundred miles away in southern New England, and
both varieties are commonly found together in central New England. Which of the
following best explains the observed distribution pattern of the snails? - Correct
Answers -Dark-colored snails absorb more solar energy and so survive more readily in
the colder northern waters.
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? - Correct Answers -The isolation prevents gene flow; thus,
the lizards on different islands experience prezygotic isolation.
A moth's color is controlled by two alleles, G and g, at a single locus. G (gray) is
dominant to g (white). A large population of moths was studied, and the frequency of the
G allele in the population over time was documented, as shown in the figure below. In
1980 a random sample of 2,000 pupae was collected and moths were allowed to
emerge.
Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what
percentage of moths in the natural population was white in 1962 ? - Correct Answers -
4%
, For following group of questions first study the description of the situation and then
choose the one best answer to each question following it and fill in the corresponding
oval on the answer sheet.
A survey reveals that 25 percent of a population of 1,000 individuals have attached
earlobes (are homozygous recessivefor the trait). For the following questions, assume
that the population fits the parameters of the Hardy-Weinberg law.
If p equals the frequency of the dominant allele and q equals the frequency of the
recessive allele, which of the following terms represents the frequency of the individuals
who show the dominant phenotype? - Correct Answers -p2 + 2pq
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? - Correct Answers -Finches with bigger
beaks are better able to crack thick-walled seeds and produce more surviving offspring.
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? -
Correct Answers -Longer beaks allow the birds to better access seeds in bird feeders.
Which of the following pieces of evidence best supports the hypothesis that birds and
crocodilians (crocodiles and alligators) are more closely related to each other than they
are to other organisms? - Correct Answers -The skulls of birds and crocodilians have an
opening that is absent in the skulls of other reptiles.
Competition for food would probably be most severe between two - Correct Answers -
closely related species in similar niches
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? - Correct Answers -The similarities between the species evolved
independently as a result of similar selective pressures in each species' environment.
