A substance introduced into the body to stimulate the production of an antibody.

A substance introduced into the body to stimulate the production of an antibody.

• A. Antigen
• B. Antibodies
• C. Allergen
• D. Gait

Answer: (A)

Antigen is the substance that the immune system recognizes as foreign and that triggers the production of antibodies. When an antigen enters the body, B cells with receptors that match it are activated, multiply, and differentiate into plasma cells that secrete antibodies specific to that antigen. These antibodies then help neutralize the invader or mark it for attack by other immune cells. An antibody is what the body makes in response to an antigen, not the trigger itself. An allergen is a type of antigen that can cause an allergic reaction in some people, but the general term for anything that provokes antibody production is antigen. Gait has no role in the immune response.

Antigen is the substance that the immune system recognizes as foreign and that triggers the production of antibodies. When an antigen enters the body, B cells with receptors that match it are activated, multiply, and differentiate into plasma cells that secrete antibodies specific to that antigen. These antibodies then help neutralize the invader or mark it for attack by other immune cells. An antibody is what the body makes in response to an antigen, not the trigger itself. An allergen is a type of antigen that can cause an allergic reaction in some people, but the general term for anything that provokes antibody production is antigen. Gait has no role in the immune response.