Question

The ABO blood group has three alleles (A, B, O). If a woman with genotype AO mates with a man with genotype BB, the expected proportion of heterozygotes among their offspring is A. 50 percent OB. 5 percent c. 100 percent D. 25 percent

Answer 1

Answer:

C. 100 percent

Explanation:

The woman is heterozygote: AO, while the man is homozygote: BB

By crossing the two:

AO   x  BB

A+B, A+B, O+B, O+B

AB, AB, OB, OB

We have two AB and two OB offspring. Both AB and OB are heterozygotes.

Thus all their offspring will be heterozygous.

Had the question asked what proportion will be OB, the answer would have been 50%.

Since the question asked, what proportion will be heterozygotes and not about the specific genotype, the correct answer is C. 100 percent