Which of the following hormones is secreted by the thyroid gland?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Thyroxine
Hormones are chemical messengers made by endocrine glands and carried by the blood to target organs. Chemically, some are steroids, some are polypeptides and some are amino acid derivatives.
The main glands and the hormones in this question are:
Thyroid gland — thyroxine: controls the rate of metabolism.
Pancreas (islets of Langerhans) — insulin: a polypeptide that lowers blood glucose.
Ovaries — estradiol: a steroid female sex hormone that controls female characteristics and the menstrual cycle.
Testes — testosterone: a steroid male sex hormone that controls male characteristics.
Adrenal cortex — glucocorticoids and mineralocorticoids; adrenal medulla — epinephrine and norepinephrine.
So the hormone secreted by the thyroid gland is thyroxine.
NCERT (2026-27 edition):
Hormones – …
