AO1

• Circadian rhythms are biological processes which cycle in about 24 hrs e.g sleep and wake cycle
• Circadian rhythms are a patter of behaviours which occur aprroapproximately every 24hrs and which is set and reset by environmental light levels
• An example of a circadian rhythm is the sleep and wake cycle.
• Body temperature is an example to circandian rhythm
• Research shows that body temperature is at its lowest at around 4am, and sleep normally occurs when the core temps begins to drop
• The core body temperature has been closely monitored and also shows a circadian rhythm. As body temperature affects metabolic rate this may tie in with the sleepy feeling we have at 2pm!