Question

The antigen-binding region of an antibody is formed by the ________.

A) constant region composed of two light chains
B) constant region composed of a heavy chain and a light chain
C) variable region composed of two light chains
D) variable region composed of two heavy chains
E) variable region composed of a heavy chain and a light chain

Answer 1

The antigen-binding region of an antibody is formed by the variable region composed of a heavy chain and a light chain. The variable regions of the heavy and light chains interact to form the binding site through which an antibody can bind a specific epitope on an antigen.

Step-by-step explanation:

The antigen-binding region of an antibody is formed by the variable region composed of a heavy chain and a light chain. All antibody molecules have two identical heavy chains and two identical light chains, and the antigen-binding sites are located at the ends of the molecule. The variable regions of the heavy and light chains interact to form the binding site through which an antibody can bind a specific epitope on an antigen.