Question

When closely related individuals mate with each other, or inbreed, the offspring are often not as fit as the offspring of two unrelated individuals. Why?

a) Inbreeding increases genetic diversity.
b) Inbreeding decreases the frequency of harmful recessive alleles.
c) Inbreeding leads to the expression of deleterious recessive alleles.
d) Inbreeding enhances the overall fitness of the population.

Answer 1

Inbreeding can bring together harmful mutations and decrease fitness in offspring. Close relatives are genetically incompatible, and inbreeding can cause normally silent alleles to be expressed.

Step-by-step explanation:

Inbreeding can bring together rare, deleterious mutations that lead to harmful phenotypes. Close relatives are genetically incompatible, and the DNA of close relatives can react negatively in the offspring. Inbreeding causes normally silent alleles to be expressed, which can result in reduced fitness and increased susceptibility to disease.