AP BIO Quick10: Mechanisms & Modes of Evolution

Which of the following best describes genetic drift?

• A process where allele frequencies change due to random events

• A process where allele frequencies change due to natural selection

• A process where allele frequencies change due to gene flow

• A process where allele frequencies change due to mutation

How does nonrandom mating affect a population's genetic structure?

• It increases genetic diversity by introducing new alleles

• It decreases genetic diversity by favoring certain alleles

• It has no effect on genetic diversity

• It causes genetic drift

Which of the following is an example of a mutation leading to variation in a population?

• A population of birds migrating to a new area

• A random change in a DNA sequence that results in a new trait

• A preference for mates with similar phenotypes

• A decrease in population size due to a natural disaster

Gene flow can best be described as:

• The movement of alleles between populations

• The random loss of alleles in a small population

• The increase in allele frequency due to advantageous traits

• The decrease in genetic variation due to selective mating

Which scenario is an example of disruptive selection?

• A population of rabbits where medium-sized individuals are favored

• A population of birds where both small and large beaks are favored over medium-sized beaks

• A population of fish where larger individuals are consistently favored

• A population of plants where only the tallest individuals survive

Which of the following best describes the effect of stabilizing selection in a population?

• It increases genetic diversity by introducing new alleles

• It reduces genetic diversity by favoring average traits

• It leads to the formation of new species

• It increases the frequency of extreme traits

In what way does genetic drift differ from natural selection?

• Genetic drift is a random process, while natural selection is not

• Genetic drift always increases genetic diversity, while natural selection does not

• Genetic drift only occurs in large populations, while natural selection occurs in all population sizes

• Genetic drift requires a selective pressure, while natural selection does not

How can gene flow counteract the effects of genetic drift?

• By increasing the population size

• By introducing new alleles into a population

• By reducing the mutation rate

• By increasing the rate of nonrandom mating

Which of the following is a potential consequence of nonrandom mating?

• Increased genetic variation within a population

• Decreased likelihood of genetic drift

• Increased frequency of homozygous individuals

• Increased gene flow between populations

What role does mutation play in the process of evolution?

• It acts as the primary mechanism of natural selection

• It introduces new genetic variations into a population

• It eliminates harmful alleles from a population

• It stabilizes allele frequencies over time