A, B, and O blood type in humans is controlled by a single gene with three alleles: I^A, I^B and i. Type O is the recessive trait. The i allele is recessive to both I^A and I^B. Which of the following could be possible genotypes of the parents of a person with type O blood?

Question

Quizplus · Accepted Answer

For a person to have type O blood (genotype ii), both parents must carry at least one i allele. Option D (I^Ai and I^Bi) allows for the possibility of both parents passing the i allele to the offspring.

A, B, and O Blood Type in Humans Is Controlled