Question

What is epistasis? What is the difference between dominant epistasis and recessive epistasis?

Answer 1

Ans: The term epistasis describes a type of gene interaction when one gene masks or modifies the expression of another gene at distinct locus.

Dominant epistasis- The dominant allele of one gene masks the effect of either allele of another gene. In this case the classical 9:3:3:1 ratio becomes modified into 12:3:1 ratio.

Recessive epistasis- The recessive alleles of one gene locus masks the action (phenotypic expression) of alleles of another gene locus. In this case the classical 9:3:3:1 ratio becomes modified into 9:3:4 ratio.