Final answer:
Circadian rhythms are regular changes in biology or behavior that occur in a 24-hour cycle. They depend on the sun and cycle about every 24 hours. Daily cycles of behavior, including sleeping and waking, are examples of circadian rhythms.
Step-by-step explanation:
Circadian rhythms are regular changes in biology or behavior that occur in a 24-hour cycle.
They depend on the sun and cycle about every 24 hours.
Daily cycles of behavior, including sleeping and waking, are examples of circadian rhythms.
These rhythms are controlled by a biological clock located in the brain, which sends signals to the body causing regular changes in behavior and body processes.