Endocrine Glands & Hormones — NEET Biology MCQs with Solutions
Free NEET Biology Endocrine Glands & Hormones MCQs with step-by-step solutions (72 questions). Part of Chemical Coordination and Integration. Practise online on Prepizo — no login needed.
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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 — Endocrine Glands & Hormones · medium · theory
Hormones act only on target cells because those cells possess specific:
A. Ducts
B. Enzymes only
C. More mitochondria
D. Receptors for the hormone ✓ Correct
Solution: A hormone affects only cells with the matching receptor (membrane-bound or intracellular).
Q4 — Endocrine Glands & Hormones · medium · theory
The gland that is both an endocrine and an exocrine gland (a "heterocrine" gland) is the:
A. Thyroid
B. Adrenal
C. Pituitary
D. Pancreas ✓ Correct
Solution: The pancreas secretes digestive enzymes (exocrine) and hormones like insulin/glucagon (endocrine).
Q5 — Endocrine Glands & Hormones · hard · theory
Protein/peptide hormones (e.g. insulin) act via membrane receptors and ______, whereas steroid hormones act by ______:
A. Digestion; osmosis
B. Being stored in the cell wall; diffusion
C. Entering the nucleus directly; second messengers
D. Second messengers (e.g. cyclic AMP); entering the cell and regulating gene expression ✓ Correct
Solution: Peptide hormones bind surface receptors and use second messengers; lipid-soluble steroids enter cells and modulate transcription.
Q6 — Endocrine Glands & Hormones · hard · theory
The organs like the heart, kidney and gastrointestinal tract are considered part of the diffused endocrine system because they:
A. Have ducts
B. Only produce enzymes
C. Store hormones
D. Also produce hormones (e.g. ANF, erythropoietin, gastrin) though not classical endocrine glands ✓ Correct
Solution: Non-endocrine organs secrete hormones too — heart (ANF), kidney (erythropoietin/renin), gut (gastrin, secretin).
Q7 — 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.
Q8 — 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.
Q9 — 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.
Q10 — 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.
Q11 — Endocrine Glands & Hormones · medium · numerical
Which statement about the chemical classification and mode of action of hormones is INCORRECT?
A. A given hormone acts only where cells possess its specific receptor
B. Thyroid hormones, though amino-acid derivatives, act like steroids inside the cell
C. Peptide hormones are water-soluble and cannot freely cross the plasma membrane
D. Steroid hormones bind cell-surface receptors and cannot enter the target cell ✓ Correct
Solution: Steroid hormones are lipid-soluble; they diffuse into the cell and bind intracellular (nuclear) receptors, not cell-surface receptors — so that statement is incorrect.
Q12 — Endocrine Glands & Hormones · medium · numerical
Assertion (A): Hormones are effective even when present in extremely small concentrations in blood. Reason (R): Their target cells carry specific high-affinity receptors that amplify the signal. Choose the correct option.
A. Both A and R are true and R is the correct explanation of A ✓ Correct
B. Both A and R are true but R is NOT the correct explanation of A
C. A is false but R is true
D. A is true but R is false
Solution: Trace amounts of hormone suffice because target-cell receptors have high affinity and trigger amplified intracellular responses; R correctly explains A.
Q13 — Endocrine Glands & Hormones · medium · numerical
A chemical is proposed to be a hormone. Which set of criteria must it satisfy to qualify as a classical hormone?
A. Non-nutrient messenger, secreted by endocrine tissue into blood, acting on distant receptor-bearing targets in trace amounts ✓ Correct
B. A nutrient carried by blood that raises the metabolic rate of every body cell
C. A neurotransmitter released only across a synaptic cleft between two neurons
D. A digestive secretion released through a duct onto an epithelial surface
Solution: A classical hormone is a non-nutrient chemical messenger secreted directly into blood by endocrine tissue and acting on distant target cells that bear specific receptors, active in trace amounts.
Q14 — Endocrine Glands & Hormones · medium · numerical
Which of the following statements about endocrine versus exocrine glands is/are correct?
(i) Endocrine glands are ductless and release secretions into blood.
(ii) Exocrine glands release their products through ducts.
(iii) The pancreas is purely an endocrine gland.
A. (ii) and (iii) only
B. (i) and (iii) only
C. (i), (ii) and (iii)
D. (i) and (ii) only ✓ Correct
Solution: Statements (i) and (ii) are correct. The pancreas is a composite (heterocrine) gland — endocrine islets plus exocrine acini — so (iii) is wrong.
Q15 — Endocrine Glands & Hormones · medium · numerical
The organised endocrine system of the human body (glands whose only role is hormone secretion) does NOT include which of the following?
A. Thyroid gland
B. Gastrointestinal tract ✓ Correct
C. Pituitary gland
D. Adrenal gland
Solution: Pituitary, adrenal, thyroid, parathyroid, pineal and gonads form the organised endocrine system; the GI tract, heart and kidney belong to the diffused endocrine system.
Q16 — Endocrine Glands & Hormones · medium · numerical
Catecholamines (adrenaline and noradrenaline) and thyroxine, though chemically classed as amino-acid derivatives, differ mainly because:
A. Both are steroids synthesised from cholesterol
B. Thyroxine is lipid-soluble and acts on intracellular receptors, whereas catecholamines are water-soluble and act on membrane receptors ✓ Correct
C. Catecholamines enter the nucleus while thyroxine stays outside the cell
D. Both act exclusively through cell-surface receptors and cAMP
Solution: Both derive from tyrosine, but thyroxine is lipid-soluble and works through intracellular receptors like a steroid, while catecholamines are water-soluble and act via membrane receptors.
Q17 — Endocrine Glands & Hormones · medium · theory
According to the current scientific definition, hormones are:
A. Nutrient chemicals which act as intracellular messengers and are produced in trace amounts
B. Non-nutrient chemicals which act as intracellular messengers and are produced in huge amounts
C. A chemical produced by endocrine glands, released into blood and transported to a distantly located target organ
D. Non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts ✓ Correct
Solution: The modern definition describes hormones as non-nutrient chemicals acting as intercellular messengers produced in trace amounts.
Q18 — Endocrine Glands & Hormones · medium · theory
The classical definition of a hormone is:
A. A non-nutrient chemical which acts as an intracellular messenger produced in trace amounts
B. A nutrient chemical produced by exocrine glands and released through ducts
C. A chemical produced by endocrine glands, released into blood and transported to a distantly located target organ ✓ Correct
D. A non-nutrient chemical which acts as an intercellular messenger produced in trace amounts
Solution: Classically a hormone was defined as a chemical made by an endocrine gland, poured into blood and carried to a distant target organ.
Q19 — Endocrine Glands & Hormones · medium · theory
Assertion: A special kind of coordination and integration has to be provided in our body and this is carried out by hormones. Reason: The nerve fibres do not innervate all cells of the body and the cellular functions need to be continuously regulated.
A. Both assertion and reason are true and reason is the correct explanation of the assertion ✓ Correct
B. Assertion is true but reason is false
C. Both assertion and reason are true but reason is not the correct explanation of the assertion
D. Both assertion and reason are false
Solution: Because neurons cannot reach every cell, hormonal coordination is required, making the reason the correct explanation of the assertion.
Q20 — Endocrine Glands & Hormones · medium · theory
Which of the following groups does NOT consist of organised (classical) endocrine glands?
A. Liver, kidney, heart and gastrointestinal tract ✓ Correct
B. Adrenal, parathyroid, thymus
C. Pancreas, testis, ovary
D. Pituitary, pineal, thyroid
Solution: Liver, kidney, heart and GI tract are not organised endocrine glands though they secrete some hormones under the newer definition.
Q21 — Endocrine Glands & Hormones · hard · theory
Among the following, how many hormones are polypeptide/protein in nature? Insulin, Glucagon, Adrenaline, LH, Prolactin, GnRH, TCT, Aldosterone, Thyroxine
A. 7
B. 5
C. 8
D. 6 ✓ Correct
Solution: Insulin, Glucagon, LH, Prolactin, GnRH and TCT are peptide/protein hormones (6); adrenaline and thyroxine are amino-acid derivatives and aldosterone is a steroid.
Q22 — Endocrine Glands & Hormones · hard · theory
Select the correct matches (Endocrine gland - Hormone - Disorder due to deficiency): (a) Neurohypophysis - Vasopressin - Diabetes insipidus (b) Adrenal cortex - Corticoids - Addison's disease (c) Parathyroid glands - Parathormone - Myxoedema (d) Thyroid gland - Calcitonin - Acromegaly
A. c, d
B. b, c
C. a, d
D. a, b ✓ Correct
Solution: Vasopressin deficiency causes diabetes insipidus and corticoid deficiency causes Addison's disease; myxoedema is a thyroid disorder and acromegaly results from growth hormone excess.
Q23 — Endocrine Glands & Hormones · medium · theory
ANF (Atrial Natriuretic Factor) is secreted by the
A. Juxtaglomerular cells of kidney
B. Ventricular wall of heart
C. G-cells of GIT
D. Atrial wall of heart ✓ Correct
Solution: ANF, which lowers blood pressure, is secreted by the atrial wall of the heart.
Q24 — Endocrine Glands & Hormones · medium · theory
Erythropoietin hormone which stimulates erythropoiesis (formation of RBC) is secreted by
A. Blood platelets
B. JG cells of the kidney ✓ Correct
C. Megakaryocytes
D. Cells of the bone marrow
Solution: Erythropoietin is secreted by the juxtaglomerular (JG) cells of the kidney.
Q25 — Endocrine Glands & Hormones · medium · theory
Which hormone stimulates secretion of water and bicarbonate ions from the pancreas?
A. Gastrin
B. Secretin ✓ Correct
C. GIP
D. Cholecystokinin (CCK)
Solution: Secretin acts on the exocrine pancreas to stimulate secretion of water and bicarbonate ions.
Q26 — Endocrine Glands & Hormones · medium · theory
Which hormone stimulates the secretion of pancreatic enzymes from the pancreas?
A. Cholecystokinin (CCK) ✓ Correct
B. GIP
C. Secretin
D. Gastrin
Solution: CCK acts on the pancreas and gall bladder, stimulating secretion of pancreatic enzymes and bile.
Q27 — Endocrine Glands & Hormones · medium · theory
Several non-endocrine tissues secrete hormones called ______; these factors are essential for the normal growth of tissues and their repair/regeneration.
A. Regeneration factor
B. Maturation factor
C. Developing factor
D. Growth factor ✓ Correct
Solution: Growth factors secreted by non-endocrine tissues are essential for normal growth, repair and regeneration.
Q28 — Endocrine Glands & Hormones · hard · theory
Which of the following organs in mammals does not consist of a central medullary region surrounded by a cortical region?
A. Ovary
B. Liver ✓ Correct
C. Adrenal
D. Kidney
Solution: Adrenal, kidney and ovary show a cortex-medulla organisation, whereas the liver does not.
Q29 — Endocrine Glands & Hormones · medium · theory
Which hormone is not secreted by an endocrine gland?
A. T4
B. PTH
C. ADH
D. ANF ✓ Correct
Solution: ANF is secreted by the heart (a non-endocrine organ), while ADH, PTH and T4 are from endocrine glands.
Q30 — Endocrine Glands & Hormones · medium · theory
Which of the following hormone is produced by non-endocrine glands?
A. Thyrocalcitonin
B. Melatonin
C. Insulin
D. Erythropoietin ✓ Correct
Solution: Erythropoietin is produced by the kidney (a non-endocrine organ); the others come from endocrine glands.