Answer: 1/4 (4 out of 16 offsprings express one of the two dominant alleles)
Explanation:
The dominant alleles are A and B
At the end of the cross AaBb x AaBb, 16 offsprings would result. They are as follows: AABB, AABb, AaBB, AaBb
AABb, AAbb, AaBb, AABB,
AaBB, AaBb, aaBB, aaBb,
AaBb, Aabb, aaBb, aabb.
Of all, only 4 offsprings (aaBb, aaBB, AAbb, Aabb) expresses one of the A or B. so 4/16 = 1/4
