Each immunoglobin has two heavy chains & two light chains, the antigen binding site is present in

Options

A. Variable region of heavy chain
B. Variable region of both heavy and light chain
C. Variable region of light chain
D. Constant region of both light and heavy chain

Answer

B

Explanation

(b) Each antibody consists of 4 polypeptides - teo heavy chains & two light chains joined to form a 'Y' shaped molecule. The amino acid sequence in the tips of the 'Y' varies greatly among different antibodies. This variable region, composed of 110-130 aminoacid, give the antibody its specificity for binding antigen. The variable region includes the ends of the light & heavy chains.