• apoptosis •
Part of Speech: Noun, mass (No plural)
Meaning: Genetically programmed cell death, sometimes called 'cell suicide', which plays an important role in shaping the distinct forms of tissues in living organisms.
Notes: The term has been used more broadly in biology since Sydney Brenner, H. Robert Horvitz and John E. Sulston received the 2002 Nobel Prize for their research of this process. The adjective is apoptotic [æ-pêp-tah-tik] and the adverb, apoptotically.
In Play: The loss of a tadpole's tail as it becomes a frog is accomplished by apoptosis, the death of those cells making up the tail. Apoptosis also accounts for the formation of the fingers and toes of a human fetus: they are shaped by the death of cells between them as the fetus develops.
Word History: Today's word is a simple transliteration of Greek apoptosis "falling off" from apoptein "to fall off", a verb based on apo- "from" + piptein "to fall." The ultimate root here is PIE *pet-/pot-/pt-, which shows up in both English feather and hippopotamus! It is associated with flying and turns up in Russian pt-ica "bird" and the name of the dinosaur with the fingers on its wings, the pterodactyl, from Greek pteron "feather, wing" and daktylos "finger". (Today's Good Word resulted from another flight of the imagination of Luciano Eduardo de Oliveira, the Brazilian Dude of our ever-growing Agora.)
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