Apoptosis

**Definition:** A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, i.e., DNA FRAGMENTATION. It is genetically programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.

**Tree numbers:** - G04.146.954.035

**Synonyms:** - Classic Apoptosis - Classical Apoptosis - Programmed Cell Death, Type I