You are looking at the color of feathers in ducks and find that yellow ducks (Y) are dominant to green ducks (y). However, a second gene, H, controls whether the color will be expressed in the feathers. If the duck is hh, the duck will always be white, because the pigment does not go into feathers. What ratio of phenotypes would you expect following a dihybrid cross?
A) 15:1
B) 12:3:1
C) 9:3:4
D) 9:6:1
E) 13:3

Question

Quizplus · Accepted Answer

The correct ratio is 9:3:4, which results from a dihybrid cross where one gene affects the expression of another. In this case, 9 will be yellow (Y_), 3 will be green (yy), and 4 will be white (hh) regardless of the Y gene because hh prevents color expression.

You Are Looking at the Color of Feathers in Ducks