Biological clock may refer to:
- Circadian rhythm, living organisms' adaptations to solar related rhythms
- Age and female fertility
Famous quotes containing the words biological and/or clock:
“Man’s biological weakness is the condition of human culture.”
—Erich Fromm (1900–1980)
“The clock of communism has stopped striking. But its concrete building has not yet come crashing down. For that reason, instead of freeing ourselves, we must try to save ourselves from being crushed by its rubble.”
—Alexander Solzhenitsyn (b. 1918)