AP BIOLOGY

Detailed explanation-1: -The immune system has a vital role: It protects your body from harmful substances, germs and cell changes that could make you ill. It is made up of various organs, cells and proteins.

Detailed explanation-2: -The immune system recognizes invaders by their antigens, which are proteins on the surface of the invading cells (see Figure 1). Every cell or substance has its own specific antigens, and a person’s cells carry “self-antigens” that are unique to that individual.

Detailed explanation-3: -There are many different types of immune cells in your body. Different cells fight different types of cancer. For example, one way the immune system fights cancer is by sending out a special form of white blood cells called T cells: The T cells see cancer as “foreign” cells that don’t belong in the body.

Detailed explanation-4: -A cell with molecules on its surface that are not identical to those on the body’s own cells is identified as being foreign. The immune system then attacks that cell. Such a cell may be a cell from transplanted tissue or one of the body’s cells that has been infected by an invading microorganism or altered by cancer.

Detailed explanation-5: -In the case of cancer antigens, the protein or part of a protein on the surface of the cancer cell or substance that alerts the immune system. This causes the production of antibodies or creates T cells that can recognize and potentially destroy the cancer cell expressing that antigen.