Circadian rhythms

Question 1

Circadian rhythm

Answer 1

A pattern of behaviour that occurs or recurs approximately every 24 hours, and which is set and reset by environmental light levels

Question 2

Sleep-wake cycle

Answer 2

Alternating states of sleep and waking that are dependent on the 24-hour circadian cycle

Question 3

Infradian rhythms

Answer 3

Rhythms that have a duration of over 24 hours, and may be weekly, monthly or even annually

Question 4

Ultradian rhythms

Answer 4

Cycles that last less than 24 hours, such as the cycle of sleep stages that occur throughout the night

Question 5

Endogenous pacemakers

Answer 5

Mechanisms within the body that govern the internal, biological bodily rhythms

Question 6

Exogenous zeitgebers

Answer 6

An envirnomental cue, such as light, that helps to regulate the biological clock in an organism