Question

The expression of one gene sometimes prevents the expression of another gene at a different chromosome. What is this phenomenon called?

• A. Polyploidism
• B. Genetic inhibition
• C. Telosuppression
• D. Epistasis

Answer 1

The correct option is D Epistasis

Epistasis is the phenomenon where the effect of one gene (locus) is dependent on the presence of one or more 'modifier genes', i.e. the genetic background. Originally the term meant that the phenotypic effect of one gene is masked by a different gene (locus). Thus, epistatic mutations have different effects in combination than individually. It was originally a concept from genetics but is now used in biochemistry, computational biology and evolutionary biology. It arises due to interactions, either between genes, or within them, leading to non-linear effects. Epistasis has a large influence on the shape of evolutionary landscapes, which leads to profound consequences for evolution and evolvability of phenotypic traits.

So the correct option is 'epistasis'.