Question

What is expressed when both alleles for a gene are equally expressed as in human blood type?

Answer 1

Its AB blood group in human; a phenotype when both alleles for ABO blood group are present in genotype. The alleles are codominant thus both are expressed.

Explanation:

Alleles of ABO blood group are responsible for producing specific antigens on surface of RBCs. In AB blood group, both A and B antigens are expressed, i.e. present on RBC.

(In individuals with O blood group, neither antigen is present on RBC.)