Question

Which among the following gland acts as a biological clock?

• A. Pineal gland
• B. Thyroid gland
• C. Adrenal gland
• D. Thymus gland

Answer 1

The correct option is A

Pineal gland

The pineal gland is an endocrine gland found in the brain. It produces and secretes the hormone melatonin, which is a hormone that helps regulate our sleep and wake cycles. The secretion of melatonin is inhibited by light and triggered by darkness. So, when the level of melatonin increases, we feel sleepy and when it decreases we wake up. Thus, this gland acts as a biological clock.