Question

In humans, the H gene that encode a connector enzyme has an epistatic effect on the I gene that codes for surface proteins on blood cells. Match each genotype to its correct phenotype.

1. IAIA or IAi; HH: type A blood, blood cells have A proteins on surface.
2. IBIB or IBi; Hh: type B blood, blood cells have B proteins on surface.
3. IAIB or IBi; hh: type O blood, blood cells lack either A or B proteins on surface.

Answer 1

The ABO blood types in humans are expressed through different alleles and genotypes. The IAIA or IAi genotype corresponds to type A blood, with A proteins on the surface of blood cells. The IBIB or IBi genotype corresponds to type B blood, with B proteins on the surface. The IAIB or IBi genotype, combined with the hh genotype, results in type O blood, where blood cells lack either A or B proteins. The correct option is 1. IAIA or IAi; HH: type A blood, blood cells have A proteins on the surface.

Step-by-step explanation:

The ABO blood types in humans are expressed as the IA, IB, and i alleles. The IA allele encodes the A blood group antigen, IB encodes B, and i encodes O. Both A and B are dominant to O. If a person has the IAIA or IAi genotype, they will have type A blood, and their blood cells will have A proteins on the surface.

If a person has the IBIB or IBi genotype, they will have type B blood, and their blood cells will have B proteins on the surface. If a person has the IAIB or IBi genotype and the hh genotype, they will have type O blood, and their blood cells will lack either A or B proteins on the surface. The correct option is 1. IAIA or IAi; HH: type A blood, blood cells have A proteins on the surface.