ANATOMY

Detailed explanation-1: -An antigen is a marker that tells your immune system whether something in your body is harmful or not. Antigens are found on viruses, bacteria, tumors and normal cells of your body.

Detailed explanation-2: -Antigens are proteins that are found on the surface of the pathogen. Antigens are unique to that pathogen. The whooping cough bacterium, for example, will have different antigens on its surface from the TB bacterium. When an antigen enters the body, the immune system produces antibodies against it.

Detailed explanation-3: -An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune system does not recognize the substance, and is trying to fight it off. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen.

Detailed explanation-4: -What is an Antigen? “An antigen is a molecule that initiates the production of an antibody and causes an immune response.” Antigens are large molecules of proteins, present on the surface of the pathogen-such as bacteria, fungi viruses, and other foreign particles.

Detailed explanation-5: -In general, two main divisions of antigens are recognized: foreign antigens (or heteroantigens) and autoantigens (or self-antigens). Foreign antigens originate from outside the body.