AP BIOLOGY

Detailed explanation-1: -There are two major pathways leading to apoptosis in the mammalian system: an extrinsic pathway initiated by death receptors and an intrinsic pathway that occurs through the mitochondria (Figure 1). The extrinsic pathway depends on binding of appropriate exogenous mediators to death receptors at the cell surface.

Detailed explanation-2: -Apoptosis can eliminate infected or cancerous cells For instance, this may be the case for cells with DNA damage, pre-cancerous cells, and cells infected by viruses. If these cells undergo apoptosis, the threat to the rest of the organism (such as cancer or spread of a viral infection) is removed.

Detailed explanation-3: -Apoptosis is a process. And this is true, too. Apoptosis allows cells to be marked for death and thus the cell can get rid of it.

Detailed explanation-4: -Apoptosis is characterised by a series of typical morphological features, such as shrinkage of the cell, fragmentation into membrane-bound apoptotic bodies and rapid phagocytosis by neighbouring cells.