A child has blood group O

A child has blood group O. If the father has blood group A and mother’s blood group is B, workout the genotypes of the parents and the possible genotypes of the other offsprings.

The child with blood group O will have homozygous recessive alleles. Therefore, both the parents should be
heterozygous, i.e. the genotype of father will be {{I}^{A}} i and the mother will be {{I}^{B}} i.