Endocrine System: Hormones and Glands – NDA Biology PYQs

Question [NDA 2006-I]
The involvement of which one of the following is essential in the control of blood sugar?
(a) Adrenal
(b) Parathyroid
(c) Spleen
(d) Pancreas

Answer: (d)
The pancreas controls blood sugar through insulin and glucagon. Adrenal glands produce adrenaline and cortisol. Parathyroid regulates calcium. Spleen is part of the immune and blood system. Blood sugar control is exclusively a pancreas function.

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Question [NDA 2006-III]
Cretinism is a human disorder which is due to the under-secretion of —
(a) Adrenal hormone
(b) Cortisone hormone
(c) Glucagon hormone
(d) Thyroxin hormone

Answer: (d)
Cretinism results from severe thyroxine deficiency during early childhood. Without enough thyroxine, normal physical and mental development is disrupted. Adrenal hormone (adrenaline) controls heart rate. Cortisone is a stress hormone. Glucagon raises blood sugar. Only thyroxine deficiency causes cretinism.

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Question [NDA 2007-I]
A surge of which hormone stimulates ovulation in human females?
(a) Luteinizing hormone
(b) Estrogen
(c) Follicle stimulating hormone
(d) Progesterone

Answer: (a)
Ovulation — the release of a mature egg — is triggered by a sudden surge of LH (Luteinizing Hormone) from the pituitary gland. FSH prepares the follicle. Oestrogen builds the uterine lining. Progesterone maintains the lining after ovulation. But the specific trigger for ovulation is LH, not the others.

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Question [NDA 2007-II]
In human body, which one of the following secretes hormones as well as digestive enzymes?
(a) Oesophagus
(b) Spleen
(c) Large intestine
(d) Pancreas

Answer: (d)
The pancreas is the only organ that performs both exocrine (enzyme secretion) and endocrine (hormone secretion) functions. It releases lipase, amylase, and trypsin into the small intestine, and releases insulin and glucagon into the blood. No other organ in the options does both.

Question [NDA 2008-I]
Which one of the following glands in human body is enlarged due to goitre?
(a) Adrenal cortex
(b) Adrenal medulla
(c) Pituitary
(d) Thyroid

Answer: (d)
Goitre is the visible swelling of the thyroid gland in the neck. It happens when the thyroid cannot get enough iodine to make thyroxine. In response, it enlarges trying to capture more iodine. Adrenal glands are above the kidneys and are not involved. The pituitary is in the brain.

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Question [NDA 2009-II]
Which of the following regions/cells in the human body is involved in controlling blood sugar level?
(a) Pituitary gland
(b) Hypothalamus
(c) Spleen
(d) Islets of Langerhans

Answer: (d)
Islets of Langerhans are clusters of cells inside the pancreas. They produce insulin (when blood sugar is high) and glucagon (when blood sugar is low). The pituitary controls other glands. The hypothalamus controls the pituitary. The spleen filters blood. Blood sugar is controlled by the Islets of Langerhans.

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Question [NDA 2019-III]
Thyroid gland produces a hormone called “Thyroxine” which —
(a) controls blood glucose levels
(b) controls ovulation
(c) controls metabolic rate
(d) maintains pregnancy

Answer: (c)
Thyroxine controls the body’s metabolic rate — how fast the body uses energy. Controlling blood glucose is the role of insulin (from the pancreas). Controlling ovulation is done by LH (from the pituitary). Maintaining pregnancy is the role of progesterone (from the ovaries).

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Question [NDA 2022-II]
Which one of the following hormones increases the heartbeat in mammals?
(a) Insulin
(b) Melatonin
(c) Thyroxine
(d) Adrenaline

Answer: (d)
Adrenaline is released by the adrenal medulla during stress or excitement. It directly increases heart rate and prepares the body for rapid action. Insulin regulates blood glucose. Melatonin regulates sleep-wake cycles. Thyroxine controls metabolic rate but does not directly and rapidly increase heart rate.

Question [NDA 2025-I]
Iodized salt is a vital part of our diet as it is essential for the synthesis of —
(a) Estrogen
(b) Insulin
(c) Adrenalin
(d) Thyroxin

Answer: (d)
Iodized salt provides iodine. Iodine is used by the thyroid gland to make thyroxine. Without iodine, thyroxine cannot be produced and the thyroid enlarges (goitre). Oestrogen is made by the ovaries. Insulin is made by the pancreas. Adrenaline is made by the adrenal gland. None of these need iodine.

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Question [NDA 2025-I]
The menstrual cycle in females is controlled by hormones that are secreted by —
(a) Ovary and lacrimal gland
(b) Ovary and sebaceous gland
(c) Prostate and pituitary gland
(d) Ovary and pituitary gland

Answer: (d)
The menstrual cycle is jointly controlled by the ovary (which produces oestrogen and progesterone) and the pituitary gland (which produces LH and FSH). Lacrimal glands produce tears. Sebaceous glands produce oil for skin. Prostate gland is a male reproductive structure. Only the ovary and pituitary are involved in the menstrual cycle.

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