Question

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______________

(a) Yellow

(b) Green

(c) White

(d) You can get all

This question was addressed to me by my college professor while I was bunking the class.

The above asked question is from Epistasis topic in section Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Answer 1

Right option is (c) White

Explanation: 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.