Which of the following are animal hormones?
(A) Auxin
(B) Adrenaline
(C) Thyroxine
(D) Oestrogen
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (B), (C) and (D) only
Hormones are chemical messengers. In animals they are made by endocrine glands and carried by the blood; plants have their own hormones, made in growing parts and acting on growth.
(A) Auxin Incorrect. Auxin is a plant hormone, made at the shoot tip; it makes plant cells grow longer and causes shoots to bend towards light.
(B) Adrenaline Correct. It is made by the adrenal glands and prepares the body for an emergency, raising the heartbeat and breathing rate.
(C) Thyroxine Correct. It is made by the thyroid gland and controls the rate of metabolism; the gland needs iodine to make it.
(D) Oestrogen Correct. It is made by the ovaries and controls the female sex characters and the menstrual cycle.