A trait's heritability:
A) is the proportion of its variation that is genetic.
B) is the proportion of its variation that cannot be explained.
C) is the proportion of its variation that is the product of genes and environment.
D) is the proportion of its variation that results from the environment alone.

Question

Quizplus · Accepted Answer

Heritability is the proportion of a trait's variation that can be attributed to genetic factors. It is usually expressed as a percentage or a fraction, from 0 to 1, with higher values indicating a stronger genetic influence. Therefore, option A correctly defines heritability as the proportion of a trait's variation that is genetic. Option B is incorrect because all variation can be explained by some combination of genetic and environmental factors. Option C is incorrect because it conflates heritability with gene-environment interaction, which is a separate concept. Option D is incorrect because it suggests that environmental factors are the sole determinant of a trait's variation.

A Trait's Heritability