Coat color in mice involves the effects of multiple gene interactions. If a mouse has two recessive alleles (aa) for coat color, it is always albino no matter what the genotype of other genes involved in coat color. This is an example of
A) pleiotropy.
B) incomplete dominance.
C) codominance.
D) epistasis.
E) heterosis.

Question

Quizplus · Accepted Answer

Epistasis occurs when the expression of one gene is affected by the presence of one or more 'modifier genes'. In this case, the presence of two recessive alleles (aa) masks the expression of other genes involved in coat color, demonstrating epistasis.

Coat Color in Mice Involves the Effects of Multiple Gene