Question

What is the phenomenon called when one gene pair interacts with a second pair to control its expression by either suppressing or modifying it?

Answer 1

Epistasis is the phenomenon where one pair of gene interacts with a second pair to control its expression by masking, suppressing or modifying it. The term meant that a different gene masks the phenotypic effect of another gene. Moreover, epistasis has a large influence on the evolution of phenotypic traits.