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)
“A junky runs on junk time. When his junk is cut off, the clock runs down and stops. All he can do is hang on and wait for non-junk time to start.”
—William Burroughs (b. 1914)