Answer: Epistasis
Explanation:Epistasis is a phenomenon that occur when the presence of a gene mask/ surprise the effect of another gene.
Epistasis can be1. intra allelic i.e within gene - This implies that the presence of an allele of the same gene mask the effect of the other on the same locus
2.Inter allelic- Two different gene where the presence
of a gene mask the effect of the other.
An epistatic gene is one who expresses itself over the other gene . It could be beneficial if the gene who is effect is masked or supress is of deleterious effect.