Question

A rare recessive allele leads to infertility in humans, but individuals heterozygous for the allele are completely fertile. What effect does the infertility of the recessive homozygotes have on the genotypic frequency of recessive homozygotes in the population?

a)It will have little or no effect on the frequency over the course of a few generations.
b)It will dramatically increase the frequency over the course of a few generations.
c)It will dramatically decrease the frequency over the course of a few generations.
d)The recessive allele is maintained indefinitely in the population by overdominance.
e)Given enough time, the recessive allele will eventually be fixed in the population.

Answer 1

Infertility in recessive homozygotes will lead to a dramatic decrease in the genotypic frequency of these homozygotes over time, as they cannot reproduce and pass on the recessive allele.

Step-by-step explanation:

The effect of the infertility of the recessive homozygotes on the genotypic frequency of recessive homozygotes in the population will be a dramatic decrease over the course of a few generations. Because individuals that are homozygous for the rare recessive allele are infertile, they cannot pass on their alleles to any offspring. This means that the allele's frequency will diminish in the population unless it is maintained by other means, such as mutation or immigration of new carriers into the population. Natural selection will favor the reproductive success of heterozygous individuals who do not express the phenotype for infertility and therefore can reproduce, further decreasing the proportion of homozygous recessive individuals.