Inheritance of ABO Blood Type in Humans is an Example

Question

Inheritance of ABO blood type in humans is an example of
A)codominance.
B)complete dominance of one allele over another.
C)a gene that is coded by more than two alleles.
D)all of the above

Accepted Answer

The ABO blood type is an example of codominance (A) because both A and B alleles can be expressed simultaneously. It also involves complete dominance (B) as the O allele is recessive to both A and B alleles. Additionally, it is coded by more than two alleles (C) as there are three alleles involved: A, B, and O.