Which of the following scenarios describes an example of epistasis?
A) Albino corn snake result from animals having recessive genotypes for each of two genes.
B) In many mammals one genotype (ee) prevents any fur color from developing.
C) In fruit flies white eyes can be due alleles of a gene on the X chromosome or a combination of other genes.
D) In cacti, there several genes control 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', i.e., the genetic background. In choice B, the genotype (ee) prevents any fur color from developing, regardless of the alleles present at other loci that normally control fur color, exemplifying epistasis where one gene's expression masks the effect of another gene.

Which of the Following Scenarios Describes an Example of Epistasis