Which one of the following is coded by the ABO blood group locus in the human genome?

Q. Which one of the following is coded by the ABO blood group locus in the human genome?

(A) Acyl transferase

(B) Galactosyltransferase

(C) Transposase

(D) β-Galactosidase

Ans: Galactosyltransferase

Solution:

(B) Galactosyltransferase

The ABO blood group locus in the human genome codes for the enzyme Galactosyltransferase. This enzyme is responsible for the transfer of specific sugar residues (galactose) to the surface of red blood cells, determining the ABO blood group system.

The ABO blood group system consists of four main blood types: A, B, AB, and O. These blood types are determined by the presence or absence of specific sugar antigens on the surface of red blood cells. Galactosyltransferase adds either a galactose sugar (for blood type A) or a different galactose sugar (for blood type B) to the H antigen, which is present in individuals with blood type O. The presence of both A and B antigens on red blood cells results in blood type AB.

Acyl transferase (A), Transposase (C), and β-Galactosidase (D) are enzymes involved in different cellular processes, but they are not directly associated with the ABO blood group system.