Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

The phenomenon by which a gene suppresses the phenotypic expression of a nonallelic gene is called epistasis. The ratio for epistatic gene is $12:3:1$ in $F_2$ generation. The alleles which do not show dominant recessive relationship and are able to express themselves independently when present together are called codominant alleles. Supplementary genes are a pair of nonallelic genes, one of which produces its effect independently in the dominant state while the dominant allele of the second gene is without any independent effect but is able to modify the effect of the former to produce a new trait.