BIO 101 EXAM 4 ACTUAL PAPER 2026
COMPLETE QUESTIONS AND SOLUTIONS
CERTIFICATION READY
◉ Approximately one out of every 2500 caucasians in the United
States is born with the recessive disease cystic fibrosis. according to
the hardy-weinberg equation, approximately what portion of
caucasians carries this condition?
Answer: 4%
◉ A gene in a population has two alleles A and a. The frequency of
the A allele in the population is 60%. We observe this population for
over five generations and we determine that no mutations occurred
in this Gene, natural selection was absent, and no gene flow has
occurred. After five generations the frequency of the a allele is
expected to be
Answer: 40%
◉ if a tsunami struck a small island and eliminated all but a small
group of lizards this would be an instance of
Answer: Bottleneck effect
◉ Which of the following is the best example of gene flow?
, Answer: Wind blows pollen from one population of plants to
another, cross fertilization occurs
◉ Genetic drift is the result of
Answer: chance
◉ after surviving a bottleneck a population recovers to the point
where it consists of as many individuals as it did prior to the
bottleneck. Which of the following statements is most likely to apply
to this population?
Answer: The post-bottleneck population exhibits less genetic
variation than the pre-bottleneck population.
◉ In a population of bears, which is most likely to be considered to
have the greatest Darwinian fitness
Answer: The bear that leaves the most descendants.
◉ Critics like to point out that theory of evolution is flawed because
it is based on random changes: mutations. They say that a random
change in an organism (or a car or TV set) is likely to harm it, not
make it function better. What statement refutes these critics?
Answer: Mutation is random, but natural selection has a non-
random "sorting" effect.
COMPLETE QUESTIONS AND SOLUTIONS
CERTIFICATION READY
◉ Approximately one out of every 2500 caucasians in the United
States is born with the recessive disease cystic fibrosis. according to
the hardy-weinberg equation, approximately what portion of
caucasians carries this condition?
Answer: 4%
◉ A gene in a population has two alleles A and a. The frequency of
the A allele in the population is 60%. We observe this population for
over five generations and we determine that no mutations occurred
in this Gene, natural selection was absent, and no gene flow has
occurred. After five generations the frequency of the a allele is
expected to be
Answer: 40%
◉ if a tsunami struck a small island and eliminated all but a small
group of lizards this would be an instance of
Answer: Bottleneck effect
◉ Which of the following is the best example of gene flow?
, Answer: Wind blows pollen from one population of plants to
another, cross fertilization occurs
◉ Genetic drift is the result of
Answer: chance
◉ after surviving a bottleneck a population recovers to the point
where it consists of as many individuals as it did prior to the
bottleneck. Which of the following statements is most likely to apply
to this population?
Answer: The post-bottleneck population exhibits less genetic
variation than the pre-bottleneck population.
◉ In a population of bears, which is most likely to be considered to
have the greatest Darwinian fitness
Answer: The bear that leaves the most descendants.
◉ Critics like to point out that theory of evolution is flawed because
it is based on random changes: mutations. They say that a random
change in an organism (or a car or TV set) is likely to harm it, not
make it function better. What statement refutes these critics?
Answer: Mutation is random, but natural selection has a non-
random "sorting" effect.
