Final answer:
The letters on blood cells represent the type of antigens present on the surface of the cells. In the ABO blood group system, the IA allele encodes the A blood group antigen. When someone has the genotype I^A, it means they have the A antigen on their blood cells.
Step-by-step explanation:
The letters on blood cells represent the type of antigens present on the surface of the cells. The letters on blood cells represent the type of antigens present on the surface of the cells. In the ABO blood group system, the IA allele encodes the A blood group antigen. When someone has the genotype I^A, it means they have the A antigen on their blood cells.
In the ABO blood group system, there are three main alleles: IA, IB, and i. The IA allele encodes the A blood group antigen, the IB allele encodes the B antigen, and the i allele does not encode any antigen. When someone has the genotype I^A, it means they have the A antigen on their blood cells.