NEET2026ZoologyPrinciples of Inheritance and VariationActual
For a person with blood group ‘O’, which of the following is not a possible combination of parents' blood group genotypes ?
Options
- AFather : I^A I^B and Mother : I^A i
- BFather : I^A i and Mother : I^B i
- CFather : I^A i and Mother : I^A i
- DFather : I^B i and Mother : I^B i
Correct answer
A. Father : I^A I^B and Mother : I^A i
Step-by-step solution
Blood group 'O' corresponds to the homozygous recessive genotype ii . For a child to have blood group 'O', they must inherit one i allele from each parent. This means both parents must possess at least one i allele in their genotype. In the combination Father : I^A I^B and Mother : I^A i , the father does not have an i allele. Therefore, he can only pass either an I^A or an I^B allele to the offspring. As a result, it is impossible for this couple to produce a child with the ii genotype (blood group 'O'). In all ot