Chemical Coordination and IntegrationNEET MCQs with solutions
Chemical Coordination and Integration covers every endocrine gland, the hormones it secretes, how hormones act on target cells and what goes wrong when they are too high or too low. NEET questions test gland–hormone–function matching and hormone disorders.
- Class
- 11 Biology
- Free on this page
- 24 questions
- In the RankUp app
- 599 questions
- ELITE questions
- 59
- NCERT topics
- 4
Practise 24 questions
Tap an option to check it. Questions from every NCERT topic in this chapter, from easy to hard.
Q1Endocrine Glands and Hormones
Thymus undergoes gradual reduction in size after puberty due to:
Not quite — the answer is B.
Thymus involutes progressively after puberty — though T cells already educated persist. This is a normal physiological process, not pathological. Increased thymosin would be expected to maintain, not reduce, thymus size.
Q2Endocrine Glands and Hormones
Vasopressin (ADH) exerts its antidiuretic effect primarily by acting on:
Not quite — the answer is B.
ADH increases water permeability of distal convoluted tubule and collecting duct via aquaporin insertion. It does not act on the proximal tubule or loop of Henle — common wrong options in NEET papers.
Q3Endocrine Glands and Hormones
Thymosin secreted by thymus is essential for:
Not quite — the answer is D.
Thymosin promotes T lymphocyte differentiation — critical for cell-mediated immunity. Thymus involutes after puberty, but its early role in establishing T cell repertoire is permanent. B lymphocyte activation is driven by antigen and helper T cells, not thymosin.
Q4Endocrine Glands and Hormones
Zona fasciculata, the middle layer of adrenal cortex, primarily secretes:
Not quite — the answer is A.
Zona fasciculata (middle) → glucocorticoids. Mineralocorticoids come from glomerulosa (outer); androgens from reticularis (inner); catecholamines from medulla. Remembering GFR from outside-in is the standard mnemonic.
Q5Endocrine Glands and Hormones
Which of the following correctly distinguishes prolactin from oxytocin regarding milk?
Not quite — the answer is C.
Prolactin (anterior pituitary) → milk synthesis; oxytocin (posterior pituitary) → milk ejection via myoepithelial contraction. Option B reverses the roles — the highest-frequency wrong answer on this topic.
Q6Endocrine Glands and Hormones
Pancreas is described as a heterocrine gland because it:
Not quite — the answer is A.
Heterocrine means a gland with both exocrine (digestive enzymes via ducts) and endocrine (insulin, glucagon via blood) functions. The islets of Langerhans constitute the endocrine component.
Q7Endocrine Glands and Hormones
Pineal gland is called the 'third eye' in lower vertebrates because:
Not quite — the answer is B.
In lower vertebrates, the pineal gland is directly photosensitive and mediates light-dependent responses — analogous to a visual organ. In mammals, it receives photic input via retinohypothalamic tract.
Q8Role of Hormones as Messengers
Which type of endocrine stimulus involves one hormone triggering secretion of another?
Not quite — the answer is A.
Hormonal stimulus occurs when a tropic hormone (e.g., TSH) stimulates a target endocrine gland (thyroid) to secrete its hormone. Humoral stimulus (Option C) involves changes in blood ion/nutrient levels — not one hormone acting on another gland.
Q9Role of Hormones as Messengers
Hormonal effects generally last longer than neural effects primarily because hormones:
Not quite — the answer is A.
Hormones bound to plasma proteins are protected from rapid enzymatic degradation, extending their half-life and effect duration. Option B is incorrect — molecular size does not determine duration; many large peptide hormones have short half-lives.
Q10Role of Hormones as Messengers
Which of the following BEST illustrates synergistic hormonal interaction?
Not quite — the answer is A.
Synergism occurs when two hormones produce a combined effect greater than either alone — GH and cortisol both promote fat breakdown and together enhance lipolysis synergistically. Option B is antagonism, not synergism.
Q11Role of Hormones as Messengers
Which of the following correctly explains the slower onset of hormonal responses compared to neural responses?
Not quite — the answer is B.
Hormones are released into the bloodstream and must reach target organs via circulation, taking minutes to hours. Option A is a trap — gene transcription is required for steroid hormone action but is not the primary reason for slower onset compared to neural conduction.
Q12Role of Hormones as Messengers
The opposing actions of insulin and glucagon in blood glucose regulation best exemplify:
Not quite — the answer is C.
Insulin lowers blood glucose while glucagon raises it; their opposing actions maintain glucose homeostasis. Synergism (Option B) is a trap — synergistic hormones enhance each other's effects, which is the opposite of what insulin-glucagon do.
575 more questions on this chapter are waiting in the app
Every one with a detailed explanation, plus flashcards and chapter tests.
Get RankUp on Google PlayQ13Mechanism of Hormone Action
Hormones acting via membrane receptors generally produce:
Not quite — the answer is A.
Second messenger cascades are rapidly activated and rapidly degraded, producing fast but transient effects. Steroid hormones (Options B) act via gene transcription with slow onset but prolonged duration.
Q14Mechanism of Hormone Action
IP₃ (inositol trisphosphate) primarily causes:
Not quite — the answer is D.
IP₃ binds receptors on the endoplasmic reticulum membrane, triggering Ca²⁺ release into the cytosol. This Ca²⁺ then activates calmodulin and other calcium-dependent proteins. Option A (cAMP) belongs to the separate adenylate cyclase pathway.
Q15Mechanism of Hormone Action
Which of the following correctly explains why lipid-soluble hormones can regulate gene expression directly?
Not quite — the answer is A.
Lipid-soluble hormones diffuse through the membrane, bind cytoplasmic/nuclear receptors, and the complex binds HREs on DNA to modulate transcription. Option B incorrectly places cAMP in the nucleus. Option C describes peptide hormone indirect nuclear signaling.
Q16Mechanism of Hormone Action
Hormone specificity of action is primarily determined by:
Not quite — the answer is C.
Only cells expressing the specific receptor for a hormone will respond to it — this is the molecular basis of target organ specificity. High hormone concentration (Option A) can increase effect magnitude but does not confer specificity.
Q17Mechanism of Hormone Action
Which molecule serves as the intracellular receptor for steroid hormones before nuclear translocation?
Not quite — the answer is C.
Steroid hormones bind specific cytoplasmic receptor proteins; the hormone-receptor complex then translocates to the nucleus. Option B (zinc-finger protein) is a tempting trap — zinc fingers ARE found in steroid receptor DNA-binding domains, but the receptor itself is a cytoplasmic protein.
Q18Mechanism of Hormone Action
Water-soluble hormones primarily act through:
Not quite — the answer is B.
Hydrophilic hormones cannot cross the lipid bilayer; they bind membrane receptors and activate second messengers like cAMP or IP₃. Option A and D describe steroid hormone action. Option C is the steroid receptor location.
Q19Disorders of Endocrine System
Which symptom is more characteristic of hyperthyroidism than hypothyroidism?
Not quite — the answer is A.
Excess T3/T4 increases mitochondrial uncoupling and metabolic rate, producing heat intolerance, tachycardia, and weight loss. Options B, C, D are all hypothyroid features — the question tests directional knowledge of thyroid hormone effects. Cold intolerance (Option C) is a particularly effective trap as students confuse heat vs cold intolerance direction.
Q20Disorders of Endocrine System
Excess aldosterone secretion would most directly produce:
Not quite — the answer is D.
Aldosterone increases Na⁺/water reabsorption (raising BP) and promotes K⁺ excretion — producing hypertension with hypokalemia (Conn syndrome). Option A is the inversion trap: hypotension and hyperkalemia are features of Addison disease (aldosterone deficiency). Options B and C involve unrelated systems.
Q21Disorders of Endocrine System
Excess PTH in hyperparathyroidism raises blood calcium primarily by:
Not quite — the answer is A.
PTH activates osteoclasts to resorb bone matrix, releasing Ca²⁺ into circulation; it also increases renal Ca²⁺ reabsorption and activates vitamin D for intestinal Ca²⁺ absorption. Option C is the trap — PTH actually increases (not decreases) renal Ca²⁺ reabsorption. Calcitonin is antagonistic to PTH.
Q22Disorders of Endocrine System
Which endocrine disorder is most directly associated with a subnormal basal metabolic rate?
Not quite — the answer is B.
Thyroid hormones are the primary regulators of BMR; adult hypothyroidism (myxoedema) lowers BMR causing lethargy, weight gain, and cold intolerance. Graves disease is the trap — also thyroid-related but causes elevated BMR. Cushing raises glucose metabolism but not BMR in the classical sense.
Q23Disorders of Endocrine System
A child shows stunted growth with normal intelligence and proportionate body. This best indicates:
Not quite — the answer is B.
Pituitary dwarfism (GH deficiency) causes proportionate stunting with normal mental development. Cretinism is the elite trap: also shows stunted growth but additionally causes mental retardation and disproportionate features due to thyroid hormone deficiency. Normal intelligence rules out cretinism.
Q24Disorders of Endocrine System
Hyposecretion of growth hormone during childhood causes:
Not quite — the answer is C.
GH deficiency during growth years stunts linear growth, producing pituitary dwarfism. Gigantism and acromegaly are both hypersecretion disorders — opposite aetiology. Cushing syndrome involves adrenal cortex excess, not GH.
ELITE question · AIR under 50 level
This chapter has 59 ELITE questions for students aiming at the very top. They are only in the app.
Unlock ELITE questions in the appGland, hormone and disorder
Quick revision: most questions in this chapter test these facts.
| Gland | Hormones and key facts |
|---|---|
| Hypothalamus | Releasing hormones (e.g. GnRH) and inhibiting hormones (e.g. somatostatin) reach the pituitary through the portal system |
| Anterior pituitary | GH, prolactin, TSH, ACTH, LH, FSH; excess GH → gigantism (child) or acromegaly (adult); deficiency → pituitary dwarfism |
| Posterior pituitary | Stores and releases oxytocin and vasopressin (ADH), which are made in the hypothalamus |
| Pineal gland | Melatonin — diurnal (24-hour) rhythm |
| Thyroid | T₄ and T₃ (need iodine), thyrocalcitonin; hypothyroidism in pregnancy → cretinism; in adults → myxoedema; iodine deficiency → goitre; Graves' disease → exophthalmic goitre |
| Parathyroid | PTH raises blood Ca²⁺ (hypercalcaemic); thyrocalcitonin lowers it |
| Thymus | Thymosins — differentiation of T-lymphocytes; the gland shrinks with age |
| Adrenal medulla | Adrenaline and noradrenaline — emergency (fight or flight) hormones |
| Adrenal cortex | Glucocorticoids (cortisol) from zona fasciculata; mineralocorticoids (aldosterone) from zona glomerulosa; androgens from zona reticularis; underproduction → Addison's disease |
| Pancreas (islets of Langerhans) | α cells: glucagon (raises blood sugar); β cells: insulin (lowers blood sugar); lack of insulin → diabetes mellitus |
| Gonads | Testis: Leydig cells make androgens (testosterone); ovary: oestrogen from follicles, progesterone from corpus luteum |
| Other organs | Heart: ANF lowers blood pressure; kidney: erythropoietin; gut: gastrin, secretin, CCK, GIP |
| Mechanism of action | Protein hormones use membrane receptors and second messengers (cAMP, IP₃, Ca²⁺); steroid and thyroid hormones use intracellular receptors and change gene expression |
What the app covers in this chapter
599 questions in total, each with a detailed explanation.
| Endocrine Glands and Hormones | 80 |
| Role of Hormones as Messengers | 80 |
| Mechanism of Hormone Action | 80 |
| Disorders of Endocrine System | 100 |
| Mixed practice and chapter tests | 259 |
Questions students ask
Is Chemical Coordination and Integration important for NEET?
Yes. It is a matching-heavy chapter: questions ask which gland secretes a hormone, what the hormone does, and which disorder results from too much or too little of it.
Which topics should I revise first?
Use the gland table on this page to learn every gland–hormone–function pair, then the disorders of GH, thyroid, adrenal and insulin, and finish with the mechanism of hormone action.
How many questions from this chapter are on RankUp?
The RankUp app has 599 questions on Chemical Coordination and Integration, including 59 ELITE questions written for students aiming at AIR under 50. Every question has a detailed explanation.
Can I download these questions as a PDF?
Yes. The free PDF on this page has all 24 questions with the answer key and explanations. No signup is needed.
