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:
“No further evidence is needed to show that “mental illness” is not the name of a biological condition whose nature awaits to be elucidated, but is the name of a concept whose purpose is to obscure the obvious.”
—Thomas Szasz (b. 1920)
“Stands the Church clock at ten to three?
And is there honey still for tea?”
—Rupert Brooke (1887–1915)