biological clock
1. any mechanism that allows expression of specific genes at periodic intervals. 2. any physiological factor that regulates body rhythms. See clock mutants.
breeding cycle
A cycle of sexual and parental behaviour and physiology. Among animals living at middle and high latitudes, the breeding cycle is usually seasonal.The reproductive physiology of seasonal breeders is ...
chronobiology
The branch of biology concerned with biological rhythms. See biological clock, biological rhythm. See also alpha wave, basic rest-activity cycle, beta wave, circadian rhythm, circannual rhythm, delta ...
circadian rhythm
Any 24-hour periodicity in the behaviour or physiology of animals or plants. Examples are the sleep/activity cycle in many animals and the growth movements of plants. Circadian rhythms are generally ...
hibernation
A strategy for surviving winter cold that is characteristic of some mammals. Metabolic rate is reduced to a minimum and the animal enters a deep sleep, surviving on food reserves stored in the body ...
infradian rhythm
Any biological rhythm with a period of less than a day. See alpha wave, basic rest-activity cycle, beta wave, delta wave, gamma wave, sensorimotor rhythm, theta wave. See also biological clock, ...
ultradian
adj. denoting a biological rhythm or cycle that occurs more frequently than once in 24 hours. Compare circadian; nyctohemeral.
