AP BIOLOGY

Detailed explanation-1: -If cells are no longer needed, they commit suicide by activating an intracellular death program. This process is therefore called programmed cell death, although it is more commonly called apoptosis (from a Greek word meaning “falling off, ” as leaves from a tree).

Detailed explanation-2: -A type of cell death in which a series of molecular steps in a cell lead to its death. This is one method the body uses to get rid of unneeded or abnormal cells. The process of programmed cell death may be blocked in cancer cells. Also called apoptosis.

Detailed explanation-3: -Apoptosis is the process of programmed cell death. It is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand. In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair. Apoptosis also plays a role in preventing cancer.

Detailed explanation-4: -Apoptosis removes cells during development. It also eliminates pre-cancerous and virus-infected cells, although “successful” cancer cells manage to escape apoptosis so they can continue dividing. Apoptosis maintains the balance of cells in the human body and is particularly important in the immune system.

Detailed explanation-5: -Apoptosis occurs normally during development and aging and as a homeostatic mechanism to maintain cell populations in tissues. Apoptosis also occurs as a defense mechanism such as in immune reactions or when cells are damaged by disease or noxious agents (Norbury and Hickson, 2001).