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Chemical Coordination and Integration — NEET Biology MCQs with Solutions
Free NEET Biology Chemical Coordination and Integration MCQs with step-by-step solutions covering Endocrine Glands & Hormones, Pituitary & Hypothalamus, Thyroid & Parathyroid, Adrenal & Pancreas, Other Glands & Mechanism. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — Endocrine Glands & Hormones · easy · theory
Ductless glands that secrete their products (hormones) directly into the blood are called:
A. Sweat glands
B. Endocrine glands ✓ Correct
C. Exocrine glands
D. Salivary glands
Solution: Endocrine glands lack ducts and release hormones into the blood; exocrine glands (e.g. salivary) have ducts.
Q2 — Endocrine Glands & Hormones · easy · theory
Chemical messengers secreted in small amounts that regulate distant target organs are called:
A. Hormones ✓ Correct
B. Enzymes
C. Vitamins
D. Antibodies
Solution: Hormones are non-nutrient chemical messengers acting on specific target tissues bearing receptors.
Q3 — Pituitary & Hypothalamus · easy · theory
The gland often called the "master gland" because it controls many other endocrine glands is the:
A. Pituitary gland ✓ Correct
B. Adrenal gland
C. Pineal gland
D. Thyroid gland
Solution: The pituitary secretes tropic hormones controlling other glands — hence "master gland" (itself regulated by the hypothalamus).
Q4 — Pituitary & Hypothalamus · easy · theory
A deficiency of Growth Hormone (GH) in childhood leads to:
A. Goitre
B. Gigantism
C. Acromegaly
D. Dwarfism ✓ Correct
Solution: Low GH in children causes pituitary dwarfism; excess causes gigantism.
Q5 — Thyroid & Parathyroid · easy · theory
The thyroid hormones (T₃ and T₄) require the element ______ for their synthesis:
A. Sodium
B. Calcium
C. Iodine ✓ Correct
D. Iron
Solution: Iodine is essential for thyroxine (T₄) and triiodothyronine (T₃) synthesis.
Q6 — Thyroid & Parathyroid · easy · theory
Enlargement of the thyroid gland due to dietary iodine deficiency is called:
A. Goitre ✓ Correct
B. Cretinism
C. Diabetes
D. Tetany
Solution: Iodine deficiency → low thyroxine → thyroid enlarges (simple goitre).
Q7 — Adrenal & Pancreas · easy · theory
The hormone secreted by the adrenal medulla during emergencies ("fight or flight") is:
A. Adrenaline (epinephrine) ✓ Correct
B. Insulin
C. Thyroxine
D. Melatonin
Solution: Adrenaline (and noradrenaline) from the adrenal medulla prepares the body for emergencies.
Q8 — Adrenal & Pancreas · easy · theory
The pancreatic hormone that lowers blood glucose by promoting its uptake and storage is:
A. Insulin ✓ Correct
B. Cortisol
C. Glucagon
D. Adrenaline
Solution: Insulin (from β-cells of islets) lowers blood glucose; glucagon (α-cells) raises it.
Q9 — Other Glands & Mechanism · easy · theory
The gland that secretes melatonin and regulates the sleep-wake (diurnal) cycle is the:
A. Thyroid
B. Pineal gland ✓ Correct
C. Thymus
D. Adrenal
Solution: The pineal gland secretes melatonin, which maintains the body's circadian rhythm and sleep-wake cycle.
Q10 — Other Glands & Mechanism · easy · theory
The gland that plays a major role in the development of the immune system (T-lymphocytes) is the:
A. Pituitary
B. Pancreas
C. Pineal
D. Thymus ✓ Correct
Solution: The thymus secretes thymosins that promote differentiation of T-lymphocytes; it degenerates with age.
Q11 — Endocrine Glands & Hormones · easy · numerical
Which of the following is NOT a general property of a typical hormone?
A. It serves as a nutrient or energy source for the target cells ✓ Correct
B. It is a non-nutrient chemical that acts as an intercellular messenger
C. It is produced in trace amounts yet elicits a marked response
D. It acts only on cells bearing the appropriate specific receptor
Solution: Hormones are non-nutrient chemical messengers secreted in trace amounts that act on specific receptor-bearing target cells; they are not used as nutrients or fuel.
Q12 — Endocrine Glands & Hormones · easy · numerical
On the basis of chemical nature, insulin, glucagon and pituitary hormones are grouped together as:
A. Amino-acid-derived catecholamine hormones
B. Iodothyronine (amino-acid-derived iodine) hormones
C. Steroid hormones
D. Peptide/protein hormones ✓ Correct
Solution: Insulin, glucagon and the pituitary hormones are peptide/protein hormones; steroids (e.g. cortisol) and iodothyronines (T3/T4) form the other chemical classes.
Q13 — Endocrine Glands & Hormones · easy · numerical
Cortisol, aldosterone, testosterone and estrogen share a common feature in that all of them are:
A. Peptide hormones acting on membrane receptors
B. Protein hormones acting through cAMP
C. Amine hormones derived from tyrosine
D. Steroid hormones derived from cholesterol ✓ Correct
Solution: These are all steroid hormones synthesised from cholesterol; being lipid-soluble they enter the cell and act via intracellular receptors.
Q14 — Endocrine Glands & Hormones · easy · numerical
Which one of the following pairs correctly matches an organ with the hormone it secretes as part of the diffused endocrine system?
A. Stomach — secretin
B. Liver — insulin
C. Kidney — erythropoietin ✓ Correct
D. Spleen — gastrin
Solution: The kidney secretes erythropoietin (stimulating erythropoiesis). Secretin comes from the intestine, insulin from the pancreas, and gastrin from the stomach — not the pairings given for those.
Q15 — Pituitary & Hypothalamus · easy · numerical
The pituitary gland is anatomically lodged in a bony cavity of the skull called the:
A. Sinus of the frontal bone
B. Sella turcica of the sphenoid bone ✓ Correct
C. Foramen magnum of the occipital bone
D. Internal auditory meatus of the temporal bone
Solution: The pituitary sits in the sella turcica, a saddle-shaped depression of the sphenoid bone, and is connected to the hypothalamus by the infundibular stalk.
Q16 — Pituitary & Hypothalamus · easy · numerical
Which anterior pituitary hormone stimulates the adrenal cortex to secrete its steroid hormones?
A. Thyroid-stimulating hormone (TSH)
B. Adrenocorticotropic hormone (ACTH) ✓ Correct
C. Luteinizing hormone (LH)
D. Melanocyte-stimulating hormone (MSH)
Solution: ACTH from the pars distalis acts on the adrenal cortex, chiefly stimulating glucocorticoid (cortisol) synthesis and secretion.
Q17 — Pituitary & Hypothalamus · easy · numerical
A person passing very large volumes of dilute urine and feeling constantly thirsty, due to reduced release of vasopressin, is most likely suffering from:
A. Addison's disease
B. Diabetes insipidus ✓ Correct
C. Cushing's syndrome
D. Diabetes mellitus
Solution: Deficient ADH (vasopressin) reduces water reabsorption in the kidney tubules, causing diabetes insipidus — copious dilute urine (diuresis) and excessive thirst.
Q18 — Pituitary & Hypothalamus · easy · numerical
Oxytocin, released from the posterior pituitary during childbirth, chiefly acts to:
A. Cause vigorous contraction of uterine smooth muscle ✓ Correct
B. Increase glucose reabsorption in kidney tubules
C. Stimulate the thyroid to release T3 and T4
D. Promote reabsorption of water in the collecting duct
Solution: Oxytocin stimulates strong contraction of the uterine smooth muscle at parturition and also causes milk ejection from the mammary glands.
Q19 — Thyroid & Parathyroid · easy · numerical
The thyroid gland consists of two lobes on either side of the trachea, connected by a connective-tissue bridge called the:
A. Isthmus ✓ Correct
B. Infundibulum
C. Pars intermedia
D. Sella turcica
Solution: The two thyroid lobes are joined across the trachea by a thin flap of connective tissue called the isthmus.
Q20 — Thyroid & Parathyroid · easy · numerical
Which thyroid hormone lowers blood calcium levels by acting on bone and kidney?
A. Parathormone (PTH)
B. Triiodothyronine (T3)
C. Thyroxine (T4)
D. Calcitonin (thyrocalcitonin) ✓ Correct
Solution: Calcitonin, secreted by the thyroid, is a hypocalcemic hormone; it lowers blood Ca2+ by inhibiting bone resorption and promoting calcium loss in urine.
Q21 — Thyroid & Parathyroid · easy · numerical
Thyroid hormones raise the basal metabolic rate. Their over-secretion (hyperthyroidism) would therefore be expected to cause:
A. Weight gain with a lowered basal metabolic rate
B. A drop in body temperature and lethargy
C. No change in body weight or metabolism
D. Weight loss with an elevated basal metabolic rate ✓ Correct
Solution: Excess thyroid hormone increases the basal metabolic rate, accelerating catabolism and typically causing weight loss despite normal or increased appetite.
Q22 — Thyroid & Parathyroid · easy · numerical
The number of parathyroid glands normally embedded on the back of the thyroid in humans is:
A. One
B. Six (three pairs)
C. Two (one pair)
D. Four (two pairs) ✓ Correct
Solution: Humans typically have four parathyroid glands — two pairs — located on the posterior surface of the thyroid lobes.
Q23 — Adrenal & Pancreas · easy · numerical
Each adrenal gland has two morphologically and functionally distinct regions, namely the:
A. Outer medulla and inner cortex
B. Outer cortex and inner medulla ✓ Correct
C. Pars distalis and pars nervosa
D. Isthmus and follicle
Solution: The adrenal gland comprises an outer cortex (steroid-secreting) and an inner medulla (catecholamine-secreting).
Q24 — Adrenal & Pancreas · easy · numerical
The pancreatic hormone that raises blood glucose by stimulating glycogenolysis in the liver is:
A. Somatostatin
B. Glucagon ✓ Correct
C. Aldosterone
D. Insulin
Solution: Glucagon, from the α-cells of the islets of Langerhans, is a hyperglycemic hormone that promotes breakdown of hepatic glycogen (glycogenolysis), raising blood glucose.
Q25 — Adrenal & Pancreas · easy · numerical
The adrenal medullary hormones are collectively called catecholamines because both are derived from the amino acid:
A. Tryptophan
B. Glycine
C. Tyrosine ✓ Correct
D. Glutamate
Solution: Adrenaline and noradrenaline are catecholamines synthesised from the amino acid tyrosine.
Q26 — Adrenal & Pancreas · easy · numerical
Aldosterone, a mineralocorticoid of the adrenal cortex, mainly promotes the reabsorption of ______ and excretion of ______ by the kidney tubules.
A. glucose; amino acids
B. Na+ and water; K+ and phosphate ✓ Correct
C. bicarbonate; calcium
D. K+ and phosphate; Na+ and water
Solution: Aldosterone stimulates renal reabsorption of Na+ and water while promoting the excretion of K+ and phosphate, thereby maintaining electrolyte, body-fluid and blood-pressure balance.
Q27 — Other Glands & Mechanism · easy · numerical
The pineal gland secretes melatonin, whose principal role is the regulation of:
A. Water reabsorption in the kidney
B. The rate of spermatogenesis only
C. Blood calcium homeostasis
D. The 24-hour (diurnal) rhythms and the sleep-wake cycle ✓ Correct
Solution: Melatonin from the pineal gland regulates the diurnal (circadian) rhythm of the body, including the sleep-wake cycle, besides influencing metabolism, pigmentation and the menstrual cycle.
Q28 — Other Glands & Mechanism · easy · numerical
The peptide hormones thymosins, important for the differentiation of T-lymphocytes, are produced by the:
A. Pineal gland
B. Adrenal medulla
C. Thymus gland ✓ Correct
D. Parathyroid gland
Solution: Thymosins from the thymus promote differentiation of T-lymphocytes and thus cell-mediated immunity, also stimulating antibody production.
Q29 — Other Glands & Mechanism · easy · numerical
In the male, the Leydig (interstitial) cells of the testis secrete androgens whose functions include:
A. Development of secondary sexual characters and stimulation of spermatogenesis ✓ Correct
B. Reabsorption of sodium in the kidney
C. Control of the circadian rhythm
D. Regulation of blood calcium levels
Solution: Testicular androgens (mainly testosterone) drive the development of male accessory sex organs and secondary sexual characters and stimulate spermatogenesis.
Q30 — Other Glands & Mechanism · easy · numerical
During the second half of the menstrual cycle, progesterone secreted mainly by the corpus luteum functions to:
A. Lower blood calcium levels
B. Stimulate spermatogenesis in the male
C. Trigger ovulation from the mature follicle
D. Maintain the uterine endometrium in readiness for/support of pregnancy ✓ Correct
Solution: Progesterone from the corpus luteum supports pregnancy by maintaining the endometrium (and later acts on the mammary glands), while estrogen governs female secondary sexual characters.