Question

The process that involves intergenic suppression or the masking effect which one gene locus has upon the expression of another is called as
A) Epistasis
B) Dominance
C) Incomplete dominance
D) Recessive
E) Pleiotropy

Answer 1

Hint: Gene interaction occurs when two or more allelic or non-allelic genes of the same genotype influence the result of particular phenotypic effects. One of the examples such as pigmentation in mice represents the process of intergenic suppression.

Complete answer:
Option (A) is correct. Epistasis is a phenomenon in genetics that involves the interaction between the genes that would influence the phenotype. It is the process that involves the intergenic suppression or the masking effect which one gene locus has upon the expression of another.
Option (B) is incorrect. In genetics, dominance is the process in which the dominant allele of a gene on a chromosome masks the effect of recessive alleles of the same gene present on the other copy of the chromosome.
Option (C) is incorrect. Incomplete dominance is a phenomenon in genetics in which the dominant allele does not completely mask the effects of a recessive allele, and the phenotype of the organism shows the characteristics that blend with both the two alleles.
Option (D) is incorrect. The recessive condition involves the expression of traits only when the genotype is in homozygous condition.
Option (E) is incorrect. Pleiotropy is a condition that occurs when one gene influences two or more seemingly unrelated phenotypic traits.

Hence, the correct option is (A).

Note: Epistasis arises due to interactions, either between the genes or within the genes that will produce non-additive effects. Thus, in epistasis, two independent non-allelic genes affect the same trait of an individual in such a manner that one over-masks the expression of the other.