Question

which blood type would not be possible for children of a type ab blood mother and a type a blood father?
a
ab
o
b

Explanation:

Step1: Determine the genotypes

The mother has blood type AB, so her genotype is \(I^{A}I^{B}\). The father has blood type A. His genotype could be \(I^{A}I^{A}\) or \(I^{A}i\).

Step2: Analyze possible offspring genotypes

• If the father's genotype is \(I^{A}I^{A}\):
• Using Punnett square: \((I^{A}I^{B})\times(I^{A}I^{A})\) gives \(I^{A}I^{A}\) (blood type A) and \(I^{A}I^{B}\) (blood type AB).
• If the father's genotype is \(I^{A}i\):
• Using Punnett square: \((I^{A}I^{B})\times(I^{A}i)\) gives \(I^{A}I^{A}\) (blood type A), \(I^{A}i\) (blood type A), \(I^{A}I^{B}\) (blood type AB), and \(I^{B}i\) (blood type B).

Step3: Conclude the impossible blood type

In both cases (father's genotypes \(I^{A}I^{A}\) or \(I^{A}i\)), there is no combination that can result in the \(ii\) genotype (blood type O). So blood type O is not possible for their children.

Answer:

C. O