Chemical Coordination and Regulation Question 23
23. The 24 hour (diurnal) rhythm of our body such as the sleep-wake cycle is regulated by the hormone :
(a) calcitonin
(b) prolactin
(c) adrenaline
(d) melatonin
Show Answer
Answer : d
Hints & Solutions
(d) Melatonin is a hormone that regulates the 24 hour rhythm of our body such as the sleepwake cycle etc. Melatonin is produced by pineal gland in the brain, which is responsible for operation and regulation of the biological clock in mammals.