Given the parents AABBCc × AabbCc, assume simple dominance for each trait and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent with genotype AABBCc?
A) 1/4
B) 1/8
C) 3/4
D) 3/8
E) 1

Question

Quizplus · Accepted Answer

The first parent has the genotype AABBCc, which means it has dominant alleles for A and B, and a recessive allele for C. Therefore, all of its offspring will inherit at least one dominant A and one dominant B allele, and only 1/4 of them will inherit a recessive c allele from both parents. 
The second parent has the genotype AabbCc, which means it has dominant alleles for A and C, and recessive alleles for B. Therefore, half of its offspring will inherit a dominant A allele from this parent, and half will inherit a dominant C allele from this parent. 
By independent assortment, the probability of inheriting a dominant A allele from the first parent and a dominant C allele from the second parent is 1/2 x 1/2 = 1/4. 
Therefore, the proportion of progeny expected to phenotypically resemble the first parent with genotype AABBCc is 1/4.

Given the Parents AABBCc × AabbCc, Assume Simple Dominance for Each