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:
“When human beings have been fascinated by the contemplation of their own hearts, the more intricate biological pattern of the female has become a model for the artist, the mystic, and the saint. When mankind turns instead to what can be done, altered, built, invented, in the outer world, all natural properties of men, animals, or metals become handicaps to be altered rather than clues to be followed.”
—Margaret Mead (1901–1978)
“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)