epistatic effect, in which the dihybrid cross 9:3:3:1 between AaBb x AaBb is modified as

1. interaction between two alleles of the same loci
2. dominance of one allele on another allele of the same loci
3. interaction between two allele oof different loci
4. dominance of one allele on another allele of both loci

Epistatic effect, in which the dihybrid cross 9:3:3:1 between AaBb x AaBb is modified as interaction between two alleles of different loci.
Epistasisis when the effect of onegenedepends on the presence of one or more 'modifier genes' (genetic background). Similarly, epistaticmutationshave different effects in combination than individually.