Question

With respect to ABO blood groups, how many genotypes and phenotypes respectively are possible in the population of human beings?

• A. 6 and 4
• B. 4 and 6
• C. 4 and 4
• D. 6 and 6

Answer 1

The correct option is A

6 and 4

The correct option is A

Explanation of the correct option:

1. The ABO blood group is determined by three alleles of the gene ‘I’ which is accountable for forming surface antigen on RBCs.
2. The three alleles are I^A, I^B and i.
3. These three alleles join together to form 6 types of genotypes.
4. Since I^A and I^B are codominant over i, there are 4 types of phenotypes possible, i.e. A, B, AB and O.

Final answer: With respect to ABO blood groups, 6 and 4 genotypes and phenotypes,respectively are possible in the population of human beings.