Question

allele frequency refers to the fraction of individuals with a particular version of a given gene. what effect does natural selection have on the allele frequency of a population? a. it increases the frequency of alleles that improve a species’ survival in a particular environment. b. it causes random changes and the allele frequency of certain traits may increase or decrease. c. it causes the allele frequency to resemble that of a small number of individuals that became separated from the rest of the population. d. it greatly reduces the total population, which increases the effects of genetic drift on allele frequency.

Explanation:

To determine the effect of natural selection on allele frequency, we analyze each option:

• Option A: Natural selection favors alleles that enhance survival and reproduction in a given environment. Over time, these beneficial alleles become more common in the population, so this matches the role of natural selection.
• Option B: Random changes in allele frequency are characteristic of genetic drift, not natural selection, so B is incorrect.
• Option C: This describes the founder effect (a type of genetic drift), where a small group's allele frequencies influence a new population, not natural selection.
• Option D: Reducing population size and increasing genetic drift effects is related to bottlenecks (genetic drift), not natural selection.

Answer:

A. It increases the frequency of alleles that improve a species’ survival in a particular environment.