Apoptosis

(see Wikiwand version and our other useful terms such as autopoiesis, pride and shame)

Cell suicide

• The normal (biochemical and morphological) processes by which a cell (e.g. within a more complex organism) kills itself. 
• It may either be initiated because it senses cell stress
• or because of (a lack of affirmative) signals from adjacent cells.

i.e. OR

A programmed process

• Apoptosis cannot stop once it has begun and follows a regulated sequence of changes. 
• Excessive apoptosis causes atrophy in the organism
• An insufficient level results in uncontrolled cell proliferation, such as cancer. 

Further reading

• Maturana, H. & Varela, F.,(1992). The Tree of Knowledge; biological roots of understanding. Boston: Shambala.
• Maturana, H. & Varela, F. (1980). “Autopoiesis and Cognition; the realisation of the Living.” In Boston Studies in Philosophy of Science. Boston: Reidel.
• Wyllie, A.H., 1997. Apoptosis: an overview. British medical bulletin, 53(3), pp.451-465.