Question

Differentiate between dominance and epistasis.

Answer 1

Sr. No.	Dominance	Epistasis
1.	Dominance is the phenomenon where one allele of a gene masks the expression of its homologous allele in a heterozygote.	Epistasis involves interaction between two different genes (non-allelic genes) where one gene masks or inhibits the expression of another gene.
2.	It occurs between alleles of the same gene at a single locus.	It involves interaction between genes located at different loci.
3.	Dominance explains the relationship between alleles of a single gene.	Epistasis explains gene interactions affecting a phenotype involving multiple genes.
3.	It shows the dominant allele phenotype in the heterozygous condition while the recessive allele phenotype is suppressed.	A gene in epistasis can completely or partially mask the expression of another gene, regardless of its alleles.
4.	It is observed in the F1 generation of monohybrid crosses where one trait dominates the other.	It is observed in dihybrid or polyhybrid crosses where two or more genes control a single trait.
5.	Examples of dominance include Mendelian dominant-recessive inheritance patterns.	Examples of epistasis include certain coat color patterns in animals where one gene affects the pigment production controlled by another gene.