Q.Fruit colour in squash is an example of

Step 1. In summer squash, one locus carries a dominant allele W for white fruit and a recessive allele w for coloured fruit; a second locus carries dominant G for yellow and recessive g for green.

Step 2. Because the dominant W allele masks the phenotypic expression of the second locus entirely, any genotype carrying at least one W allele is white regardless of its G/g genotype - this masking by a dominant allele at one locus of a different locus's expression is the definition of dominant epistasis. …

Match the example (summer squash fruit colour, 12:3:1 ratio) to its named intera …

• Confusing dominant epistasis (12:3:1) with recessive epistasis (9:3:4). …