Question

Select the incorrect pairs form the following.
A. Melanocyte stimulating hormone regulates skin pigmentation.
B. Diurnal rhythm of our body is regulated by the hormone melatonin.
C. The main glucocorticoid present in our body's cortisol.
D. Calcitonin is secreted by parathyroid gland.
E. Iodine is essential for the synthesis and secretion of parathyroid hormones.

• A. A, C and D
• B. A, B and D
• C. D and E
• D. B and D

Answer 1

The correct option is C D and E

MSH, melanocyte stimulating hormone, is secreted by anterior pituitary and stimulates melanocytes to produce melanin in lower vertebrates. Depending on the amount of melanin and carotene, colour of skin is determined from pale yellow to dark.

Pineal gland secretes melatonin that regulates sleep-wakefulness part of circadian cycle.

Cortisol is the main glucocorticoid, secreted by adrenal cortex, which prepares the body for long term stress response by stimulating anti stress mechanisms which includes increased blood glucose level, stimulation of protein and fat metabolism, reduced inflammation etc.

Calcitonin hormone, secreted by thyroid gland in response to increased blood calcium level, stimulates temporary reduction in number and activity of osteoclasts and thereby reducing the blood calcium level to normal. Parathyroid gland secretes parathormone which serves antagonistically to calcitonin and thereby helps maintain the blood calcium level.

Thyroxine and triiodothyronine are thyroid hormones that have four and three iodine atoms respectively. This poses need of iodine for their synthesis. Parathormone is a peptide hormone that does not have iodine atoms.

Therefore, the correct answer is option C.