Question

"Suppose two independently assorting genes are involved in the pathway that determines fruit color in squash. These genes interact with each other to produce the squash colors seen in the grocery store. At the first locus, the W allele codes for a dominant white phenotype, whereas the w allele codes for a colored squash. At the second locus, the allele Y codes for a dominant yellow phenotype, and the allele y codes for a recessive green phenotype. The phenotypes from the first locus will always mask the phenotype produced by the second locus if the dominant allele (W) is present at the first locus. This masking pattern is known as dominant epistasis. A dihybrid squash, Ww Yy, is selfed and produces 320 offspring. How many offspring are expected to have the white, yellow, and green phenotypes

Answer 1

Answer:

White:120

Yellow:30

Green: 10

Explanation:

Given;

W  codes for a dominant white phenotype;

w codes for a colored squash;

the Y codes for a dominant yellow phenotype;

the y codes for a recessive green phenotype.

The phenotypes from the first locus  mask the phenotype produced by the second locus.

A dihybrid squash, of  Ww Yy, is self crossed

WwYy * WwYy

F1 are:

WWYY,WWYy, WWyy, WwYy, Wwyy,wwYy, Wwyy and wwyy etc

Due to dominant epistasis, the progeny are:

White:120

Yellow:30

Green: 10