Question

The antigen binding site of an antibody is present at -

• A. Between constant and variable region
• B. The constant region
• C. The C-terminal
• D. The variable region

Answer 1

The correct option is D The variable region

Antibodies are made up of four polypeptide chains- two heavy and two light chains. Light and heavy chains are subdivided into variable and constant regions.
The variable portion is used for binding to antigen and a constant portion determines its adherence and diffusivity.

So, the correct answer is- variable portion.