You perform a test cross of the dihybrid AaBb and score the phenotypes of 1000 progeny. Assuming independent assortment, how many of the progeny do you expect to display the dominant phenotype for both the A and B genes?
A)100
B)200
C)250
D)500
E)750

Question

Quizplus · Accepted Answer

In a test cross of a dihybrid AaBb, the expected phenotypic ratio is 1:1:1:1. Therefore, 1/4 of the progeny will display the dominant phenotype for both genes. 1/4 of 1000 is 250.

You Perform a Test Cross of the Dihybrid AaBb and Score