Final answer:
The offspring of an AB mother and a heterozygous A father can have type A, AB, or B blood. The mother can donate blood to the father, but compatibility for the father to donate to the mother depends on additional factors. An individual with type O blood cannot be a child of an AB and a heterozygous A parent.
Step-by-step explanation:
The phenotypes of the offspring from a mother with blood type AB and a father who is heterozygous for blood type A (IAi) can be determined by understanding how the ABO blood group system works. In this system, blood type AB is an example of codominance, where both IA and IB alleles are expressed equally. Therefore, a person with type AB blood expresses both A and B antigens on their red blood cells. The blood type A parent can pass on either the IA or i allele, and the AB parent can pass on either IA or IB. As such, the possible genotypes for the offspring are IAIA, IAIB, IAi, and IBi. The resulting phenotypes or blood types would be: A (from IAIA and IAi genotypes), AB (from IAIB), and B (from IBi). As the mother has both A and B antigens, she can donate blood to the father, but the reverse is not always possible without knowing the Rh factor. The blood types of the offspring could be:
- Type A (50% chance)
- Type AB (25% chance)
- Type B (25% chance)
There is no possibility for a type O offspring from this pair due to the lack of genotype ii. When it comes to blood donation, the mother (type AB) can donate to the father (type A) as AB is the universal plasma donor. However, the father may only be able to donate to the mother if he lacks the B antigen (only type A or O blood), and the compatibility for full blood transfusions also depends on the Rh factor.
An individual with blood type O (genotype ii) cannot be the biological child of a blood type A and a blood type B parent unless one parent has a genotype of AO or BO, allowing for the possibility of passing on the i allele.