What is the definition of epistasis?

Question

When a dominant allele for a specific trait is not completely expressed over the recessive allele.
When the allele of one gene interferes with the expression of another gene.
When one gene affects multiple phenotypes.
When one trait is determined by multiple genes.

Answer 1

Epistasis refers to the phenomenon in genetics where the allele of one gene interferes with or masks the expression of another gene, resulting in a deviation from the typical Mendelian inheritance patterns. It can occur when one gene affects multiple phenotypes or when one trait is determined by multiple genes.