The 24 hour (diurnal) rhythm of our body such as the sleep-wake cycle is regulated by the hormone
- calcitonin
- prolactin
- adrenaline
- melatonin
Answer
(4) melatonin
Solution
As per NCERT, the pineal gland secretes melatonin.
⇒ Melatonin plays a very important role in the regulation of the 24-hour (diurnal) rhythm of our body, e.g. it helps in maintaining the normal rhythms of the sleep-wake cycle and body temperature.
Answer: (4)