Question

If a child has blood group ‘A’ and his mother has blood group ‘A’ then, what are the possibilities of the blood group of his father?

• A. A
• B. O
• C. B
• D. All of these

Answer 1

The correct option is D All of these

The genotype of the child is either $I^A{I}^{A}or{I}^{A}i$. The mother has blood group A ($I^A{I}^{A}or{I}^{A}i$). It is possible that the father will have:

i) $I^A{I}^{A}or{I}^{A}i$ (blood group A): It is possible to have a child with blood group A as mentioned in the cross- $I^A{I}^{A}or{I}^{A}i$ X $I^A{I}^{A}or{I}^{A}i$. If $i$ or $I^A$ from father combines with either $I^A$ or $i$ from mother respectively, the child will be A blood group.

ii)$I^{B}i$ (blood group B): There is a chance that a child will have A blood group as mentioned in the cross- $I^{B}i$ X $I^A{I}^{A}or{I}^{A}i$. If $i$ from father combines with $I^A$ from mother, the child will have A type blood group.

iii) $I^A{I}^B$ (AB blood group): There is also a chance that the child will be A blood group as mentioned in the cross- $I^A{I}^B$ X $I^A{I}^{A}or{I}^{A}i$. If $I^A$coming from father combines with either $I^A$ or $i$ from mother, the child will be A type blood group.

iv) $ii$ (O blood group): There is also a possibility that the child will be A blood group as mentioned in the cross-
$ii$ X $I^A{I}^{A}or{I}^{A}i$. If $i$ from father combines with $I^A$ from mother, the child will be A type blood group.

Hence, the possibilities of the blood group of the father are A, B, AB or O.