Which of the following scenarios describes an example of epistasis?
A) Recessive genotypes for each of two genes (aabb) results in an albino snake.
B) In rabbits and many other mammals, one genotype (ee) prevents any fur colour from developing.
C) In Drosophila (fruit flies), white eyes can be due to an X-linked gene or to a combination of other genes.
D) In cacti, there are several genes for the type of spines.

Question

Quizplus · Accepted Answer

Epistasis occurs when the effect of one gene is dependent on the presence of one or more 'modifier genes'. In option B, the genotype (ee) prevents any fur color from developing, which is an example of epistasis because the presence of the ee genotype masks the expression of other genes responsible for fur color.

Which of the Following Scenarios Describes an Example of Epistasis