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:
“It is not the literal past that rules us, save, possibly, in a biological sense. It is images of the past.... Each new historical era mirrors itself in the picture and active mythology of its past or of a past borrowed from other cultures. It tests its sense of identity, of regress or new achievement against that past.”
—George Steiner (b. 1929)
“We are hardly ever grateful for a fine clock or watch when it goes right, and we pay attention to it only when it falters, for then we are caught by surprise. It ought to be the other way about.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)