STD 12 - 7. human health and disease — NEET STD 11 Science — Question

b
Antigen is a substance that when introduced in the body, stimulate the production of antibody. They are mostly proteins but may be carbohydrates, lipids, nucleic acids etc. One antigen can bind with many antibodies. Every antigen has many antigenic determinants called epitopes. The recognition ability of antibody is innate and develops without exposure to the antigen.