Question

A child of O blood group has B blood group father, the genotype of the father would be

• A. $I^O{I}^O$
• B. $I^B{I}^B$
• C. $I^A{I}^B$
• D. $I^B{I}^O$

Answer 1

The correct option is D $I^B{I}^O$

The ABO blood group in humans is an example for multiple alleles. For a child to have ‘O’ blood group i.e on the surface of RBC no antigen is present, either both parents must be in heterozygous condition or one parent homozygous O and the other heterozygous. We know that during the formation of gametes, the pair of alleles segregate from each other leading to a probability of the ‘O’ blood group. The below table is helpful in predicting the progeny blood group.
For the blood group type of ‘O’ to be present in a child, it has to be in homozygous form.

Thus, among the given options the probable genotype of the father would be $I^B{I}^O$.