What fraction of offspring of the cross AaBb $\times$ AaBb is homozygous for all the dominant alleles, assuming that they are on different chromosomes?
A) 1/4
B) 1/8
C) 1/16
D) 1/32
E) 1/64

Question

Quizplus · Accepted Answer

When the parents AaBb F1F1F1S1F1F1F10 AaBb are crossed, the possible gametes are AB, Ab, aB, and ab.
The Punnett square for this cross would look like the following:

AB      Ab      aB      ab
 F1F1F1S1 AABb  AaBb    aaBb   aabb
 F1F1F10  AABb  AaBb    aaBb   aabb

Out of the 16 possible offspring, only one genotype (AABB) has all dominant alleles. Therefore, the fraction of offspring that are homozygous for all dominant alleles is 1/16.

What Fraction of Offspring of the Cross AaBb ×\times× AaBb Is Homozygous for All the Dominant Alleles, Assuming That

What Fraction of Offspring of the Cross AaBb $\times$ AaBb Is Homozygous for All the Dominant Alleles, Assuming That