Chemical Coordination and Integration

15 NEET-UG practice questions on Chemical Coordination and Integration, part of Zoology. The first 15 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Medium

   Which of the following statements about the adrenal gland are correct? A. The medulla secretes adrenaline and noradrenaline. B. The zona glomerulosa is the innermost layer of the cortex. C. Aldosterone is the main glucocorticoid. D. Cortisol is the main glucocorticoid. Choose the correct answer.

   1. AA and D only
   2. BA, B and D only
   3. CA and C only
   4. DA, C and D only

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   Answer: A · A and D only

   The medulla secretes the catecholamines adrenaline and noradrenaline, and cortisol is the main glucocorticoid, so A and D are correct. The zona reticularis is the inner layer and the zona glomerulosa the outer one, so B is wrong. Aldosterone is the main mineralocorticoid, so C is wrong.

   • B: This accepts B, which places the zona glomerulosa on the wrong side of the cortex.
   • C: This calls aldosterone a glucocorticoid and rejects cortisol.
   • D: This accepts C, which misclassifies aldosterone.

   Remember this

   Cortex from inside out: reticularis, fasciculata, glomerulosa. Aldosterone is mineralocorticoid; cortisol is glucocorticoid.

2. Question 2 · Medium

   Match List-I with List-II. List-I (hormone) A. Gastrin B. Secretin C. Cholecystokinin D. Gastric inhibitory peptide List-II (action) I. Stimulates exocrine pancreas to secrete water and bicarbonate ions II. Inhibits gastric secretion and motility III. Stimulates gastric glands to secrete HCl and pepsinogen IV. Stimulates secretion of pancreatic enzymes and bile juice

   1. AA-II, B-I, C-IV, D-III
   2. BA-I, B-III, C-IV, D-II
   3. CA-III, B-I, C-IV, D-II
   4. DA-III, B-IV, C-I, D-II

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   Answer: C · A-III, B-I, C-IV, D-II

   Gastrin acts on gastric glands for HCl and pepsinogen. Secretin acts on the exocrine pancreas for water and bicarbonate. CCK acts on pancreas and gall bladder to give pancreatic enzymes and bile juice, and GIP inhibits gastric secretion and motility.

   • A: This swaps gastrin, which stimulates the stomach, with GIP, which inhibits it.
   • B: This swaps the targets of gastrin and secretin.
   • D: This swaps the actions of secretin and cholecystokinin.

   Remember this

   Gastrin works on the stomach; secretin and CCK work on the pancreas; GIP slows the stomach.

3. Question 3 · Medium

   Given below are two statements: Statement I: Steroid hormones bind to membrane-bound receptors and generally do not enter their target cells. Statement II: Cyclic AMP, IP₃ and Ca²⁺ can act as second messengers for hormones. Choose the correct answer.

   1. ABoth Statement I and Statement II are incorrect
   2. BStatement I is incorrect but Statement II is correct
   3. CStatement I is correct but Statement II is incorrect
   4. DBoth Statement I and Statement II are correct

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   Answer: B · Statement I is incorrect but Statement II is correct

   Steroid hormones and iodothyronines act through intracellular receptors and mostly regulate gene expression, so Statement I is wrong. It is the hormones acting on membrane-bound receptors that stay outside the cell and use second messengers such as cyclic AMP, IP₃ and Ca²⁺, so Statement II is correct.

   • A: Statement II correctly names three second messengers.
   • C: This reverses the verdict on the two statements.
   • D: Statement I is wrong, as steroids act through intracellular receptors.

   Remember this

   Peptide hormones act on membrane receptors through second messengers; steroids and iodothyronines act inside the cell on genes.

4. Question 4 · Hard

   All parathyroid tissue of a patient is removed by mistake during neck surgery, and no treatment is given. Which change is expected first?

   1. AFall in blood Ca²⁺ with muscle spasms, as PTH no longer mobilises calcium
   2. BEnlarged thyroid with low metabolism, as iodine uptake is no longer controlled
   3. CRise in blood Ca²⁺ with uric acid deposits, as calcium deposition stops
   4. DFall in blood glucose with weakness, as the glucagon supply is no longer there

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   Answer: A · Fall in blood Ca²⁺ with muscle spasms, as PTH no longer mobilises calcium

   PTH is hypercalcaemic: it raises blood Ca²⁺ through bone resorption, renal reabsorption and absorption from food. Without PTH, blood Ca²⁺ falls. Low Ca²⁺ in body fluid produces rapid muscle spasms, the condition called tetany.

   • B: Goitre relates to iodine and the thyroid, not to the parathyroids.
   • C: Removing a hypercalcaemic hormone cannot raise calcium, and uric acid deposits belong to gout.
   • D: Glucagon comes from islet alpha cells, not the parathyroids.

   Remember this

   No PTH means low blood Ca²⁺, and low Ca²⁺ in body fluid causes tetany.

5. Question 5 · Medium

   Given below are two statements: Statement I: Parathyroid hormone lowers blood Ca²⁺ by promoting its deposition in bone. Statement II: Thyrocalcitonin is a steroid hormone secreted by the parathyroid glands. Choose the correct answer.

   1. ABoth Statement I and Statement II are incorrect
   2. BBoth Statement I and Statement II are correct
   3. CStatement I is incorrect but Statement II is correct
   4. DStatement I is correct but Statement II is incorrect

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   Answer: A · Both Statement I and Statement II are incorrect

   Parathyroid hormone raises blood Ca²⁺ by stimulating bone resorption, renal reabsorption of Ca²⁺ and its absorption from digested food, so Statement I is wrong. Thyrocalcitonin is a protein hormone of the thyroid gland, so Statement II is wrong on both class and source.

   • B: Both statements contain errors of fact.
   • C: Thyrocalcitonin is a protein from the thyroid, not a parathyroid steroid.
   • D: PTH raises, not lowers, blood Ca²⁺.

   Remember this

   PTH is hypercalcaemic; thyrocalcitonin comes from the thyroid and regulates blood calcium.

6. Question 6 · Medium

   Match List-I with List-II. List-I (cells) A. Alpha cells of the islets B. Beta cells of the islets C. Leydig cells D. Juxtaglomerular cells List-II (hormone) I. Erythropoietin II. Insulin III. Androgens IV. Glucagon

   1. AA-II, B-IV, C-III, D-I
   2. BA-IV, B-II, C-III, D-I
   3. CA-II, B-IV, C-I, D-III
   4. DA-IV, B-II, C-I, D-III

   Answer and explanation in LearnFree account

7. Question 7 · Easy

   Which gland secretes melatonin, a hormone that helps regulate the 24-hour rhythm of the body?

   1. AThyroid gland
   2. BPineal gland
   3. CThymus
   4. DParathyroid gland

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8. Question 8 · Easy

   Which of these hormones is synthesised in the hypothalamus and stored in and released from the neurohypophysis?

   1. AOxytocin
   2. BAdrenocorticotrophic hormone
   3. CMelanocyte stimulating hormone
   4. DProlactin

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9. Question 9 · Medium

   Arrange the steps of male hormonal control in the correct order. A. LH acts on Leydig cells. B. The hypothalamus releases GnRH. C. Androgens stimulate spermatogenesis. D. The pars distalis releases gonadotrophins. Choose the correct order.

   1. AB, D, A, C
   2. BB, D, C, A
   3. CD, B, A, C
   4. DB, A, D, C

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10. Question 10 · Easy

    Which hormones play a major role in the differentiation of T-lymphocytes?

    1. AThyroxine
    2. BThyrocalcitonin
    3. CMelatonin
    4. DThymosins

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11. Question 11 · Hard

    Which set consists only of hormones that act through intracellular receptors?

    1. AProgesterone, epinephrine, testosterone
    2. BEstradiol, FSH, thyroxine
    3. CInsulin, glucagon, cortisol
    4. DCortisol, testosterone, thyroxine

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12. Question 12 · Medium

    Assertion A: Glucagon is a hyperglycaemic hormone. Reason R: Glucagon stimulates glycogenolysis in liver cells. Choose the correct answer.

    1. AA is not correct but R is correct
    2. BBoth A and R are correct and R is the correct explanation of A
    3. CA is correct but R is not correct
    4. DBoth A and R are correct but R is not the correct explanation of A

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13. Question 13 · Medium

    Match List-I with List-II. List-I (disorder) A. Cretinism B. Exophthalmic goitre C. Diabetes insipidus D. Pituitary dwarfism List-II (hormonal basis) I. Hypothyroidism during pregnancy II. Low ADH III. Hyperthyroidism with protruded eyeballs IV. Low growth hormone

    1. AA-I, B-III, C-II, D-IV
    2. BA-I, B-III, C-IV, D-II
    3. CA-III, B-I, C-II, D-IV
    4. DA-III, B-I, C-IV, D-II

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14. Question 14 · Easy

    Excess secretion of growth hormone in a middle-aged adult, after growth has ended, leads to

    1. Aacromegaly
    2. Bcretinism
    3. Cgigantism
    4. Dpituitary dwarfism

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15. Question 15 · Hard

    Regarding the actions of glucocorticoids, consider the following: A. They stimulate gluconeogenesis, lipolysis and proteolysis. B. They inhibit cellular uptake and utilisation of amino acids. C. Cortisol stimulates the immune response and promotes inflammation. D. Cortisol stimulates RBC production. Choose the correct answer.

    1. AA and B only
    2. BA, B, C and D
    3. CA, B and D only
    4. DA, B and C only

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