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 poetic phantasy
but a biological reality,
a fact: I am an entity
like bird, insect, plant
or sea-plant cell;
I live; I am alive.”
—Hilda Doolittle (1886–1961)
“What brought them there so far from their home,
Cuchulain that fought night long with the foam,
What says the Clock in the Great Clock Tower?
Niamh that rode on it; lad and lass
That sat so still and played at the chess?
What but heroic wantonness?”
—William Butler Yeats (1865–1939)