In case of summer squash, the W locus shows dominant epistasis over the Y locus. W locus develop white colour while /- give yellow and y/y gives green. If you cross a yellow and a green summer squash you can’t get______________

Correct Answer: White
In both the parents in this case the W locus must have homozygous recessive gene. Thus, the cross can never give a heterozygous case in W locus which is needed for development of white colour.