How many genes are responsible for ABO system of blood group in humans

1.	How many genes are responsible for ABO system of blood group in humans? (A) One (B) Two (C) three (D) four
Answer» Correct Answer is: (C) three The ABO blood group antigens are encoded by one genetic locus, the ABO locus, which has three alternative (allelic) forms—A, B, and O. A child receives one of the three alleles from each parent, giving rise to six possible genotypes and four possible blood types (phenotypes).

How many genes are responsible for ABO system of blood group in humans? (A) One (B) Two (C) three (D) four

Answer»

Correct Answer is: (C) three

The ABO blood group antigens are encoded by one genetic locus, the ABO locus, which has three alternative (allelic) forms—A, B, and O.

A child receives one of the three alleles from each parent, giving rise to six possible genotypes and four possible blood types (phenotypes).