Many of the color varieties of summer squash are determined

Many of the color varieties of summer squash are determined by several interacting loci: AA or Aa gives white, aaBB or aaBb gives yellow, and aabb produces green. Crosses among heterozygotes give a 12:3:1 ratio. What type of gene interaction would account for these results?

Solution

Answer is Dominant epistasis.... 12:3:1

In this epista allele is Dominant so onely one copy is needed to mask the other gene.