The ABO blood groups in humans are determined by a multiple-allele system in which I^A and I^B are codominant and are both dominant to I^O.If an infant born to a mother with blood type O is also type O, the father's blood type can be A) only O or A. B) only A or B. C) only O. D) O, A, or B. E) impossible to determine.

Question

Quizplus · Accepted Answer

Since the mother has blood type O, she can only pass on the "O" allele to her child. Therefore, the father must have either the "A," "B," or "O" allele in order to potentially pass it on to the child. This means the father can have blood type O, A, or B. Therefore, the correct answer is choice D.

The ABO Blood Groups in Humans Are Determined by a Multiple-Allele