Question

In cats, assume that one gene controls the color of pigment produced during fur growth, and comes in black and orange alleles. Separately, another gene controls whether any pigment produced is actually deposited in a growing hair or not. Thus, any cat homozygous for the recessive allele of the pigment deposition gene will have white fur, regardless of which combination of black or orange alleles they have for the other gene. What kind of inheritance is this an example of?

		Pleiotropy
		Polygenic inheritance
		Epistasis
		Gene-environment interaction

Answer 1

Answer - Epistasis

Explanation - Epistasis is the ineraction in which two or more different genes influence the outcome of a single trait. In other words, the expression of one gene affect the inheritance of other gene. Here the pigment deposition gene influence the effect of the gene which controls colour of pigments. So the pigment deposition gene is epistatic to the gene for colour of pigments.

Additional points -

Polygenic inheritance - a single trait is controlled by multiple genes.

Pleiotropy - multiple traits are controlled by a single gene

Gene - environment interaction - Genotype and environmental conditions affect the phenotype.