Question

If a father has type A blood and the mother has Type AB blood, they would NOT have a child with which of the following blood types?

AB

A

B

O

Answer 1

A father with type A blood and a mother with type AB blood cannot have a child with type O blood, as type O requires the inheritance of a recessive O allele from each parent, which this combination of parents does not have.

Step-by-step explanation:

The blood types of a father with type A blood and a mother with type AB blood reflect a pattern of genetic inheritance based on the ABO blood group system. Given the father's blood type, his genotype could be either AA or AO. The mother with type AB blood has a genotype of AB. In this scenario, they could have children with type A (genotype AO or AA from the father and A from the mother), type AB (from both the A and B alleles from the parents), or type B (genotype BO or BB from the father and B from the mother). However, they cannot have a child with type O blood, as this type requires both parents to contribute a recessive O allele (genotype ii), which neither of these parents has.

Children of a type A father and type AB mother can exhibit the A, B, and AB blood types depending on the combination of the parents' alleles they inherit. This pattern is evident in the observed 1:1:2 phenotype ratio for the potential offspring. The father can pass on either an A or an O allele, and the mother can pass on either an A or a B allele. The combinations result in different potential genotype outcomes: AA, AO, AB, and BB, but not OO.

Answer 2

If a father has type A blood and the mother has type AB blood, they cannot have a child with blood type O, although depending on the father's genotype, they may not have children with a B blood type either.

Step-by-step explanation:

Blood type is determined by the presence or absence of surface antigens A and B, which is genetically determined and establishes the pattern of inheritance.

Alleles that define the presence of antigens A and B are co-dominant, while the absence of antigens - as in blood type O - is a recessive trait.

• Type A contains antigen A and its genotype can be A|A or A|O.
• Type B contains the B antigen, whose genotype can be B|B or B|O.
• Blood type AB contains both antigens and a single genotypic expression A|B
• Type O blood lacks surface antigens, with genotype O|O.

The father with blood type A can have two genotypes, A|A or A|O, which raises 2 possible scenarios:

1. Father A|O with mother A|B

Alleles A O

A A|A A|O

B A|B B|O

In this case there is no chance of having a child with blood type O, 50% chance of having children with blood type A, 25% B and 25% AB.

2. Father A|A with mother A|B

Alleles A A

A A|A A|A

B A|B A|B

50% chance of having a child with blood type A and 50% with blood type AB. In this case there is no chance of having children with blood type O or B.