AP BIOLOGY

Detailed explanation-1: -Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens.

Detailed explanation-2: -An antigen is a foreign substance that enters your body. This can include bacteria, viruses, fungi, allergens, venom and other various toxins. An antibody is a protein produced by your immune system to attack and fight off these antigens.

Detailed explanation-3: -Antigens are markers that tell your body that something is foreign. Your immune cells make antibodies to recognize and destroy harmful antigens. In fact, you can think of antigens as antibody generators.

Detailed explanation-4: -antigen, substance that is capable of stimulating an immune response, specifically activating lymphocytes, which are the body’s infection-fighting white blood cells. In general, two main divisions of antigens are recognized: foreign antigens (or heteroantigens) and autoantigens (or self-antigens).

Detailed explanation-5: -In an immune response, the immune system recognizes the antigens (usually proteins) on the surface of substances or microorganisms, such as bacteria or viruses, and attacks and destroys, or tries to destroy, them. Cancer cells also have antigens on their surface.