Question

How does gene I control. ABO blood groups in humans? Write the effect of the gene on the structure of red blood cells.

Answer 1

In humans, the ABO blood groups are controlled by a gene called gene ‘I’. It has three alleles, namely IA, IB and i. A person possesses any two of the three alleles. IA and IB dominate over i. But with each other, IA and IB are codominant. These alleles help to determine the blood group of a person. The plasma membrane of red blood cells has sugar polymers that protrude out from its surface and the kind of sugar is regulated by the gene 'I' of ABO blood group. The alleles IA and IB produce A and B types of sugar, while allele I does not produce any sugar.