Chemical Coordination and Integration (NCERT Practice Paper)
Q1. Match the following organ hormones:
Organ
Hormone
A. Heart
(I) Erythropoietin
B. Kidney
(II) ANF
C. Testis
(III) Testosterone
D. Ovary
(IV) Progesterone
Correct Answer: (a)
The heart secretes ANF (II); the kidneys produce erythropoietin (I); the testes secrete testosterone (III); and the ovaries produce progesterone (IV). These are the primary hormonal products of these organs.
Q2. According to the current scientific definition, hormones are:
Correct Answer: (c)
Hormones are defined as non‑nutrient chemicals that serve as intercellular messengers. They are produced in minute (trace) quantities and are secreted by endocrine glands directly into the blood. They do not provide energy or building blocks; instead they regulate physiological processes.
Q3. On the basis of chemical nature, insulin and glucagon are ______ hormones.
Correct Answer: (c)
Insulin and glucagon are both peptide/protein hormones. Insulin is a polypeptide composed of two chains (A and B) linked by disulfide bonds, while glucagon is a single polypeptide chain. They are synthesized as larger precursor molecules and are stored in secretory vesicles until release. Their hydrophilic nature requires membrane‑bound receptors for signalling.
Q4. Match the following for thyroid conditions:
Term
Feature
A. Goitre
(I) Enlargement of thyroid gland
B. Graves' disease
(II) Protrusion of eyeballs
C. Cretinism
(III) Stunted growth in baby
Correct Answer: (a)
Goitre is characterized by thyroid enlargement (I); Graves' disease often includes exophthalmos (protruding eyes) (II); and cretinism leads to stunted growth in infants (III). These are the classic associations for these thyroid‑related conditions.
Q5. Assertion: Deficiency of iodine leads to goitre.
Reason: Iodine is essential for the synthesis of thyroid hormones.
Correct Answer: (a)
Iodine is an essential component of thyroid hormones T3 and T4. When iodine intake is insufficient, the thyroid gland cannot synthesize adequate hormones, leading to a negative feedback that increases TSH secretion. TSH stimulates the thyroid to grow, resulting in goitre. Thus, iodine deficiency directly causes goitre because it impairs hormone synthesis, and the reason correctly explains this causal relationship.
Q6. Which of the following statements about the pituitary gland are true? (i) Located in the sella tursica bony cavity. (ii) Pars distalis is commonly called anterior pituitary. (iii) Pars nervosa stores oxytocin and vasopressin. (iv) It is divided into adenohypophysis and neurohypophysis.
Correct Answer: (a)
All statements about the pituitary are correct: it sits in the sella tursica, the pars distalis is the anterior pituitary, the pars nervosa (posterior pituitary) stores oxytocin and vasopressin, and it is divided into adenohypophysis (anterior) and neurohypophysis (posterior).
Q7. Progesterone is primarily secreted by the:
Correct Answer: (b)
Progesterone is mainly produced by the corpus luteum, which forms from the ruptured ovarian follicle after ovulation. Its primary role is to prepare and maintain the endometrium for implantation of a fertilized egg and to support early pregnancy. Progesterone also helps regulate the menstrual cycle and is essential for the establishment of pregnancy.
Q8. Match the following adrenal cortex layers:
Column-I (Layer)
Column-II (Position)
A. Zona glomerulosa
(I) Inner layer
B. Zona fasciculata
(II) Middle layer
C. Zona reticularis
(III) Outer layer
Correct Answer: (a)
The adrenal cortex consists of three layers: zona glomerulosa (outermost), zona fasciculata (middle), and zona reticularis (innermost). Thus A‑III, B‑II, C‑I is correct.
Q9. Match the following for adrenal cortex hormones:
A. Cortisol
Glucocorticoid
B. Aldosterone
Mineralocorticoid
Correct Answer: (a)
Cortisol is indeed a glucocorticoid, and aldosterone is a mineralocorticoid. Both classifications are correct based on their primary actions: cortisol regulates metabolism, while aldosterone controls electrolyte balance.
Q10. Regarding the Parathyroid hormone (PTH): (i) It increases blood Ca2+ levels. (ii) It stimulates bone resorption. (iii) It increases Ca2+ reabsorption by renal tubules. (iv) It is a hypocalcemic hormone.
Correct Answer: (a)
PTH raises blood calcium by promoting bone resorption, increasing renal reabsorption, and activating vitamin D. It is a hypercalcemic hormone, not hypocalcemic, so (iv) is false. Therefore, (i), (ii), and (iii) are correct.
Q11. Underproduction of hormones by the adrenal cortex leads to:
Correct Answer: (b)
Addison’s disease is caused by insufficient secretion of hormones from the adrenal cortex, particularly cortisol and aldosterone. This leads to symptoms such as weakness, fatigue, weight loss, low blood pressure, and skin hyperpigmentation. It is a chronic condition that requires hormone replacement therapy.
Q12. Match hormone receptors with their location:
Receptor Type
Location
A. Membrane-bound
(I) Cell membrane
B. Intracellular
(II) Nucleus / Cytoplasm
Correct Answer: (a)
Membrane‑bound receptors are located on the cell membrane (I), while intracellular receptors are found in the nucleus or cytoplasm (II). This distinction is based on the solubility of the hormone; water‑soluble hormones use membrane receptors, while lipid‑soluble hormones use intracellular receptors.
Q13. Assertion: Steroid hormones usually have membrane-bound receptors.
Reason: They generate second messengers like cyclic AMP inside the target cell.
Correct Answer: (d)
Steroid hormones are lipophilic and primarily cross the plasma membrane to bind to intracellular receptors. They do not usually act through membrane‑bound receptors, and the classic genomic action involves regulation of gene transcription rather than generation of second messengers. However, some steroid hormones can also have non‑genomic effects mediated by membrane receptors and second messengers. The assertion that they usually have membrane‑bound receptors is therefore false, but the reason that they can generate second messengers is true for certain non‑genomic pathways. Hence the assertion is false but the reason is true.
Q14. After ovulation, the ruptured follicle is converted to a structure called:
Correct Answer: (b)
Following ovulation, the remnants of the ovarian follicle are transformed into the corpus luteum (yellow body). This endocrine structure secretes mainly progesterone, which is essential for maintaining the uterine lining during early pregnancy. If pregnancy does not occur, the corpus luteum degenerates into a corpus albicans.
Q15. Which element is essential for the normal rate of hormone synthesis in the thyroid?
Correct Answer: (c)
Iodine is a critical component of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). The thyroid gland actively concentrates iodide from the blood and incorporates it into the tyrosine residues of thyroglobulin. Without adequate iodine, the gland cannot produce sufficient thyroid hormones, leading to goitre and hypothyroidism.
Q16. Which are correct for 'Cortisol'? (i) Stimulates gluconeogenesis. (ii) Produces anti-inflammatory reactions. (iii) Suppresses the immune response.
Correct Answer: (a)
Cortisol is the main glucocorticoid secreted by the adrenal cortex. It stimulates gluconeogenesis in the liver, thereby increasing blood glucose levels. It also exerts powerful anti‑inflammatory effects and suppresses the immune system, which helps control excessive immune reactions and inflammation. These are well‑known actions of cortisol, making all three statements true.
Q17. Which hormone is secreted by the atrial wall of the heart to decrease blood pressure?
Correct Answer: (c)
Atrial Natriuretic Factor (ANF) is a hormone released by the atrial wall of the heart in response to increased blood volume and pressure. It acts on the kidneys to promote sodium and water excretion (natriuresis), and it also causes vasodilation. These effects collectively reduce blood pressure and volume, maintaining cardiovascular homeostasis.
Q18. Match the following secondary messengers:
Hormone Class
Mechanism
A. Protein Hormones
(I) Generate second messengers (e.g. cAMP)
B. Steroid Hormones
(II) Interaction with genome
Correct Answer: (a)
Protein hormones bind to membrane receptors and generate second messengers like cAMP (I); steroid hormones, being lipophilic, enter the cell and interact with intracellular receptors that affect gene expression (II). This matching reflects the two major modes of hormone action.
Q19. Assertion: The adrenal medulla is centrally located in the adrenal gland.
Reason: Outside the medulla lies the adrenal cortex.
Correct Answer: (b)
The adrenal medulla is indeed the inner core of the adrenal gland, and it is surrounded by the adrenal cortex. Both statements are anatomical facts. However, the reason merely describes the spatial relationship and does not explain why the medulla is located centrally—it simply states the arrangement. Thus, both are true but the reason is not the correct explanation.
Q20. Parathyroid hormone (PTH) is a ______ hormone.
Correct Answer: (b)
PTH is a hypercalcemic hormone, meaning it raises blood calcium levels. It does so by stimulating bone resorption (release of calcium from bones), increasing calcium reabsorption in the kidneys, and activating vitamin D to enhance calcium absorption from the intestine. This helps maintain calcium homeostasis.
Q21. Identify correct features of the 'Islets of Langerhans': (i) Endocrine part of the pancreas. (ii) 1 to 2 million per pancreas. (iii) Secretes gastrin.
Correct Answer: (a)
The Islets of Langerhans are the endocrine portion of the pancreas; there are about 1‑2 million islets. However, they do not secrete gastrin (which is produced by the stomach). So (i) and (ii) are correct.
Q22. Regarding the hormone 'Epinephrine': (i) Increases rate of respiration. (ii) Increases alertness. (iii) Stimulates breakdown of lipids and proteins.
Correct Answer: (a)
Epinephrine, a catecholamine, is released during stress and triggers a wide range of 'fight or flight' responses. It increases the rate of respiration to supply more oxygen to tissues, enhances mental alertness by stimulating the central nervous system, and promotes the breakdown of lipids and proteins to mobilise energy stores. All these effects are consistent with its role as an emergency hormone, so all three statements are correct.
Q23. Which hypothalamic hormone inhibits the release of growth hormone from the pituitary?
Correct Answer: (b)
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH), is produced by the hypothalamus and inhibits the secretion of growth hormone from the anterior pituitary. It also suppresses the release of thyroid-stimulating hormone and other hormones, thereby modulating overall growth and metabolism.
Q24. Androgens stimulate ______ in males.
Correct Answer: (b)
Androgens, such as testosterone, have anabolic effects and stimulate erythropoiesis (red blood cell formation) in males. They also promote the development of male secondary sexual characteristics, spermatogenesis, and protein synthesis. Erythropoiesis is enhanced by increasing the production of erythropoietin and by stimulating the bone marrow directly.
Q25. Which hormone is a hyperglycemic hormone?
Correct Answer: (b)
Glucagon is a hyperglycemic hormone because it raises blood sugar levels. It stimulates glycogen breakdown (glycogenolysis) and the synthesis of glucose from non‑carbohydrate sources (gluconeogenesis) in the liver. This action ensures that the body has an adequate supply of glucose during fasting or stress, and it is the principal counter‑regulatory hormone to insulin.
Q26. Adrenaline and noradrenaline are rapidly secreted in response to stress and are called:
Correct Answer: (b)
Adrenaline (epinephrine) and noradrenaline (norepinephrine) are catecholamines, derived from the amino acid tyrosine. They are secreted by the adrenal medulla during the 'fight or flight' response and act to prepare the body for emergency situations by increasing heart rate, blood pressure, and blood glucose levels.
Q27. Match the following for hormone action:
Hormone
Mechanism
A. FSH
(I) Membrane bound receptor
B. Estrogen
(II) Intracellular receptor
Correct Answer: (a)
FSH is a glycoprotein hormone that binds to membrane‑bound receptors (I), while estrogen, being a steroid, binds to intracellular receptors (II). This reflects the different chemical natures of these hormones.
Q28. Over-secretion of GH in adults, especially in middle age, can result in severe disfigurement called:
Correct Answer: (c)
Acromegaly is caused by excessive secretion of growth hormone after the growth plates have fused (in adulthood). This leads to thickening of bones, enlargement of hands, feet, and facial features, and other soft-tissue changes. Gigantism occurs when GH excess happens before puberty, while dwarfism is due to GH deficiency.
Q29. Which statements about the Thymus gland are correct? (i) It secretes thymosins. (ii) It is a lobular structure located behind the sternum. (iii) It degenerates in old individuals. (iv) It helps in the production of antibodies.
Correct Answer: (a)
The thymus secretes thymosins, is lobular and lies behind the sternum, undergoes involution with age, and promotes antibody production by aiding T‑cell maturation. All statements are correct.
Q30. Assertion: Insulin is a hypoglycemic hormone.
Reason: it stimulates glycogenesis in target cells.
Correct Answer: (a)
Insulin lowers blood glucose by promoting the conversion of glucose to glycogen (glycogenesis) in liver and muscle cells. It also enhances glucose uptake and inhibits gluconeogenesis. These actions collectively reduce circulating glucose levels, which is why insulin is called a hypoglycemic hormone. The reason correctly identifies glycogenesis as a key mechanism, thus providing the correct explanation.
Q31. Hormones of the adrenal medulla (catecholamines) increase:
Correct Answer: (d)
Adrenaline and noradrenaline, the catecholamines of the adrenal medulla, produce a wide range of effects during the 'fight or flight' response. They increase heart rate, enhance the force of cardiac contractions, and increase the rate of respiration. They also dilate pupils, constrict blood vessels in the skin and viscera, and promote glycogenolysis, all of which prepare the body for action.
Q32. The two lobes of the thyroid gland are interconnected with a thin flap of connective tissue called:
Correct Answer: (a)
The thyroid gland consists of two lateral lobes that are joined by a narrow band of tissue called the isthmus. This connective bridge lies across the anterior surface of the trachea. The isthmus is important for the structural integrity of the gland and ensures that both lobes function as a single endocrine unit.
Q33. Regarding the Adrenal cortex: (i) Glucocorticoids regulate carbohydrate metabolism. (ii) Mineralocorticoids regulate water and electrolyte balance. (iii) Cortisol is the main glucocorticoid. (iv) Aldosterone is the main mineralocorticoid.
Correct Answer: (a)
Glucocorticoids (like cortisol) influence carbohydrate metabolism, while mineralocorticoids (like aldosterone) regulate water and electrolyte balance. Both cortisol and aldosterone are the main representatives of their respective classes. All statements are correct.
Q34. Thyrocalcitonin (TCT) is a protein hormone that:
Correct Answer: (c)
Thyrocalcitonin (also called calcitonin) is secreted by the parafollicular cells (C cells) of the thyroid gland. Its primary action is to lower blood calcium levels by inhibiting bone resorption and promoting calcium deposition in bones. This makes it a hypocalcemic hormone, counteracting the effects of parathyroid hormone.
Q35. Hypothyroidism during pregnancy causing defective development of the baby leads to:
Correct Answer: (c)
Cretinism is a condition of severe physical and mental retardation caused by hypothyroidism in the developing foetus. It results from a deficiency of thyroid hormones during pregnancy, which are essential for normal brain development and growth. Early treatment with thyroid hormone can prevent these irreversible effects.
Q36. Exopthalmic goitre (Graves’ disease) is a form of:
Correct Answer: (b)
Graves’ disease is an autoimmune disorder that leads to hyperthyroidism, characterized by an overactive thyroid gland. The symptoms include goitre (enlarged thyroid), protruding eyeballs (exophthalmos), weight loss, increased heart rate, and anxiety. It is the most common cause of hyperthyroidism.
Q37. Endocrine glands are called ductless glands because they:
Correct Answer: (a)
Endocrine glands lack a duct system and release their hormones directly into the bloodstream. This is the defining characteristic that distinguishes them from exocrine glands, which have ducts. The absence of ducts ensures that the secreted hormones reach their target tissues via the circulatory system.
Q38. Melanocyte stimulating hormone (MSH) is secreted by:
Correct Answer: (b)
MSH is produced by the pars intermedia, a region of the pituitary that lies between the anterior and posterior lobes. MSH stimulates the production and release of melanin from melanocytes in the skin, influencing skin pigmentation. In humans, the pars intermedia is largely rudimentary but still produces MSH.
Q39. The pineal gland is located on the ______ side of the forebrain.
Correct Answer: (b)
The pineal gland is a small, cone‑shaped structure situated on the dorsal side of the forebrain, between the two hemispheres. It is attached to the roof of the third ventricle and is responsible for the secretion of melatonin, which regulates circadian rhythms.
Q40. Identify the correct statements regarding the hypothalamus: (i) It is the basal part of the diencephalon. (ii) It contains groups of neurosecretory cells called nuclei. (iii) It produces releasing and inhibiting hormones. (iv) It regulates the posterior pituitary via a portal system.
Correct Answer: (a)
The hypothalamus is the basal part of the diencephalon (i), contains neurosecretory nuclei (ii), and produces releasing/inhibiting hormones (iii). However, the posterior pituitary is regulated by direct neural connections, not a portal system (iv). So only (i), (ii), and (iii) are correct.
Q41. Which GI tract hormone stimulates the secretion of water and bicarbonate ions from the pancreas?
Correct Answer: (b)
Secretin is a hormone released by the S‑cells of the duodenum in response to acidic chyme. Its primary action is to stimulate the pancreatic duct cells to secrete a large volume of bicarbonate‑rich fluid, which neutralizes the acid entering the small intestine. It also inhibits gastric secretion and motility.
Q42. Which of the following acts as a second messenger?
Correct Answer: (b)
Cyclic AMP (cAMP) is a classic second messenger that mediates the effects of many peptide hormones. When a hormone binds to a membrane‑bound receptor, it activates adenylyl cyclase, which converts ATP to cAMP. The rise in cAMP then activates protein kinase A, leading to phosphorylation of various proteins and cellular responses. Other second messengers include IP3 and calcium ions.
Q43. Assertion: Diabetes insipidus leads to water loss and dehydration.
Reason: It is caused by the over-secretion of ADH.
Correct Answer: (a)
Diabetes insipidus is indeed characterized by excessive water loss through the kidneys, leading to polyuria and dehydration. However, this condition is caused by a deficiency of antidiuretic hormone (ADH), not its over‑secretion. The reason is therefore false. The assertion remains true because the lack of ADH prevents the kidneys from concentrating urine, causing a loss of free water.
Q44. Which part of the brain is the basal part of the diencephalon and regulates a wide spectrum of body functions?
Correct Answer: (b)
The hypothalamus is the basal region of the diencephalon, located below the thalamus. It is a crucial neuroendocrine centre that controls many autonomic functions, such as body temperature, hunger, thirst, and sleep. It also links the nervous system to the endocrine system via the pituitary gland.
Q45. Assertion: Cortisol is the main glucocorticoid in our body.
Reason: Glucocorticoids are involved in carbohydrate metabolism.
Correct Answer: (b)
Cortisol is the principal glucocorticoid, and glucocorticoids are indeed involved in carbohydrate metabolism (e.g., gluconeogenesis). However, the reason merely describes a general function of glucocorticoids; it does not specify why cortisol is the main one. Both statements are correct, but the reason does not directly explain the assertion, so the correct choice is both true but reason not the correct explanation.
Q46. Assertion: Endocrine glands are called ductless glands.
Reason: They lack ducts and release their secretions directly into the blood.
Correct Answer: (a)
Endocrine glands are indeed termed ductless because they do not possess a duct system. Instead, they secrete their hormones directly into the surrounding interstitial fluid, from where the hormones diffuse into the blood capillaries. This direct release into the bloodstream is the hallmark of endocrine glands and explains why they are called ductless. The reason accurately describes this anatomical and functional feature, making it the correct explanation for the assertion.
Q47. Select correct statements for the GI tract hormones: (i) Gastrin stimulates HCl and pepsinogen. (ii) Secretin stimulates water and bicarbonate from pancreas. (iii) CCK stimulates pancreatic enzymes and bile juice. (iv) GIP stimulates gastric secretion.
Correct Answer: (a)
Gastrin stimulates HCl and pepsinogen; secretin promotes water/bicarbonate from the pancreas; CCK stimulates pancreatic enzyme release and bile contraction; but GIP inhibits gastric secretion, not stimulates. So (i), (ii), and (iii) are correct.
Q48. The hormone that regulates the 24-hour sleep-wake cycle is:
Correct Answer: (b)
Melatonin, secreted by the pineal gland, is the primary hormone that regulates the circadian rhythm (sleep‑wake cycle). Its levels are low during the day and high at night, promoting sleep. Melatonin also has antioxidant properties and influences seasonal rhythms in some animals. Its production is suppressed by light, which is why exposure to light at night can disrupt sleep patterns.
Q49. Which of the following are correctly described by the given statements? (i) They act as intercellular messengers. (ii) They are produced in trace amounts. (iii) They are non-nutrient chemicals.
Correct Answer: (b)
Hormones are intercellular messengers, produced in very small quantities, and they are non‑nutrient chemicals—they do not provide energy or building materials. These three features are part of the modern definition of hormones, distinguishing them from enzymes, vitamins, and minerals.
Q50. The Leydig cells (interstitial cells) of the testis produce a group of hormones called:
Correct Answer: (c)
Leydig cells, located in the interstitial spaces of the testis, secrete androgens, the most important of which is testosterone. Androgens are responsible for the development of male secondary sexual characteristics, spermatogenesis, and anabolic effects on protein metabolism. Their secretion is regulated by luteinizing hormone (LH) from the anterior pituitary.
Q51. Match the following pituitary hormones with their target actions:
Column-I
Column-II
A. TSH
(I) Milk formation
B. Prolactin
(II) Thyroid hormone synthesis
C. ACTH
(III) Glucocorticoid secretion
D. MSH
(IV) Skin pigmentation
Correct Answer: (a)
TSH stimulates thyroid hormone synthesis (II); prolactin promotes milk formation (I); ACTH stimulates glucocorticoid secretion (III); and MSH stimulates skin pigmentation (IV). These are the primary functions of the respective anterior pituitary hormones.
Q52. Cholecystokinin (CCK) acts on both ______ and ______ to release enzymes and bile juice.
Correct Answer: (b)
CCK is secreted by the I‑cells of the duodenum and jejunum in response to the presence of fats and proteins in the chyme. It stimulates the pancreas to release digestive enzymes and the gall bladder to contract and release bile. Thus, CCK facilitates the digestion and absorption of fats and proteins.
Q53. Match the glands in Column-I with their locations in Column-II:
Column-I (Gland)
Column-II (Location)
A. Hypothalamus
(I) Sella tursica
B. Pituitary
(II) Basal part of diencephalon
C. Pineal
(III) Dorsal side of forebrain
D. Thymus
(IV) Between lungs behind sternum
Correct Answer: (a)
The hypothalamus is located in the basal part of the diencephalon (II); the pituitary gland sits in the sella tursica (I); the pineal gland is on the dorsal side of the forebrain (III); and the thymus lies between the lungs behind the sternum (IV). This matching follows the standard anatomical positions.
Q54. Which region of the pituitary produces growth hormone (GH) and prolactin (PRL)?
Correct Answer: (c)
The pars distalis, which is the largest part of the anterior pituitary, produces several hormones including growth hormone (GH) and prolactin (PRL). Other cells in this region secrete TSH, ACTH, FSH, and LH. The pars distalis is often referred to as the anterior pituitary and is under the control of hypothalamic releasing hormones.
Q55. Assertion: Thyrocalcitonin (TCT) and Parathyroid hormone (PTH) play opposite roles.
Reason: TCT lowers blood calcium levels while PTH increases them.
Correct Answer: (a)
TCT (calcitonin) and PTH have antagonistic effects on blood calcium. TCT decreases calcium levels by inhibiting bone resorption and promoting calcium deposition, while PTH increases calcium levels by stimulating bone resorption, renal reabsorption, and intestinal absorption. This opposing action ensures tight regulation of calcium homeostasis. The reason correctly describes these opposite physiological roles, thus providing the correct explanation for the assertion.
Q56. Assertion: Adrenaline is called the 'emergency hormone'.
Reason: It is rapidly secreted in response to stress and emergency situations.
Correct Answer: (a)
Adrenaline (epinephrine) is termed the 'emergency hormone' because it is secreted in large amounts during acute stress, preparing the body for 'fight or flight'. Its rapid release from the adrenal medulla triggers physiological changes such as increased heart rate, elevated blood pressure, and dilation of airways. These effects are all geared towards handling emergencies, which is exactly what the reason states. Hence, the reason correctly explains the assertion.
Q57. Regarding the 'Graafian follicles': (i) They grow under the influence of FSH. (ii) They secrete estrogen. (iii) They are found in the testis.
Correct Answer: (a)
Graafian follicles are mature ovarian follicles that develop from primordial follicles under the stimulation of follicle‑stimulating hormone (FSH). They produce and secrete oestrogen, which is essential for female reproductive physiology. However, they are located in the ovaries, not in the testes. Therefore, only statements (i) and (ii) are correct, and the correct option is the first one.
Q58. Which statements about male and female hormones are correct? (i) Androgens regulate spermatogenesis. (ii) Estrogen stimulates mammary gland development. (iii) Progesterone supports pregnancy. (iv) Both produce anabolic effects on metabolism.
Correct Answer: (d)
Androgens regulate spermatogenesis; estrogen stimulates mammary gland development; progesterone supports pregnancy. However, only androgens are typically described as having significant anabolic effects; estrogens and progesterone do not share this property to the same extent. Thus (iv) is false, and the correct set is (i), (ii), and (iii) only.
Q59. Identify correct descriptions for hormone classes: (i) Cortisol, testosterone, progesterone are steroids. (ii) Insulin, glucagon are proteins. (iii) Epinephrine is an amino-acid derivative. (iv) Thyroxine is an iodothyronine.
Correct Answer: (a)
All these chemical classifications are correct: cortisol, testosterone, and progesterone are steroids; insulin and glucagon are proteins; epinephrine is derived from tyrosine; and thyroxine is an iodothyronine.
Q60. Identify the correct features of catecholamines (Adrenaline/Noradrenaline): (i) They are emergency hormones. (ii) They increase heart beat and strength of contraction. (iii) They increase pupilary dilation and piloerection. (iv) They stimulate the breakdown of glycogen.
Correct Answer: (a)
Catecholamines are secreted during stress (emergency hormones); they increase heart rate and contractility, cause pupil dilation and piloerection, and stimulate glycogen breakdown to provide energy. All these effects are part of the fight‑or‑flight response.
Q61. Regarding the hormone Insulin: (i) It enhances cellular glucose uptake. (ii) It acts on hepatocytes and adipocytes. (iii) It stimulates glycogenesis. (iv) Deficiency results in diabetes insipidus.
Correct Answer: (a)
Insulin increases glucose uptake, acts on liver and fat cells, and promotes glycogen formation. However, its deficiency causes diabetes mellitus, not diabetes insipidus (which is due to ADH deficiency). Hence (i), (ii), and (iii) are correct.
Q62. Which of the following describes the 'Pancreas' correctly? (i) It is a composite gland (both exocrine and endocrine). (ii) Islets of Langerhans represent only 1-2% of pancreatic tissue. (iii) Glucagon is hyperglycemic. (iv) Insulin is hyperglycemic.
Correct Answer: (a)
The pancreas has both exocrine (digestive) and endocrine (hormonal) functions; the Islets of Langerhans comprise only 1‑2% of the pancreas; glucagon raises blood glucose (hyperglycemic); but insulin is hypoglycemic, not hyperglycemic. Thus (i), (ii), and (iii) are correct.
Q63. Match the pancreatic cell with the hormone:
Cell type
Hormone
A. Alpha-cells
(I) Glucagon
B. Beta-cells
(II) Insulin
Correct Answer: (a)
Alpha‑cells produce glucagon (I), and beta‑cells produce insulin (II). This is the classic pairing within the Islets of Langerhans, where alpha and beta cells have opposing effects on blood glucose.
Q64. Correct statements about 'Diabetes Mellitus': (i) Associated with loss of glucose through urine. (ii) Leads to formation of harmful ketone bodies. (iii) Patients are treated with insulin therapy. (iv) Caused by ADH deficiency.
Correct Answer: (a)
Diabetes mellitus leads to glucosuria, can cause ketone body formation, and is treated with insulin (for type 1). It is caused by insulin deficiency or resistance, not ADH deficiency (which causes diabetes insipidus). So (i), (ii), and (iii) are correct.
Q65. Regarding the hormone Melatonin: (i) It is secreted by the pineal gland. (ii) It regulates the 24-hour diurnal rhythm. (iii) It influences metabolism and pigmentation. (iv) It plays a role in the defense capability of the body.
Correct Answer: (a)
Melatonin is secreted by the pineal gland, regulates the circadian rhythm, influences metabolism and pigmentation, and is also involved in immune defense. All these functions are described in the chapter, making all statements correct.
Q66. Hypothalamic hormones reach the pituitary gland through which system?
Correct Answer: (c)
The hypothalamus communicates with the anterior pituitary through a specialized portal blood system called the hypophyseal portal circulation. This system carries releasing and inhibiting hormones directly from the hypothalamus to the anterior pituitary, allowing rapid and targeted control of pituitary hormone secretion.
Q67. The thymus gland secretes which peptide hormones?
Correct Answer: (b)
The thymus produces a group of peptide hormones called thymosins. These hormones are essential for the development and differentiation of T‑lymphocytes, which are key players in cell‑mediated immunity. Thymosins also promote the production of antibodies, contributing to humoral immunity.
Q68. The posterior pituitary is under the ______ regulation of the hypothalamus.
Correct Answer: (b)
The posterior pituitary (neurohypophysis) is regulated directly by the hypothalamus via neural connections. The hormones oxytocin and vasopressin are synthesized in hypothalamic neurons and transported down their axons to the posterior pituitary, where they are stored and released upon neural stimulation.
Q69. An impairment affecting the synthesis or release of ADH leads to a condition called:
Correct Answer: (b)
Diabetes insipidus results from a deficiency of antidiuretic hormone (ADH), also known as vasopressin. This leads to excessive water loss through the kidneys, producing large volumes of dilute urine and causing severe dehydration and thirst. It is distinct from diabetes mellitus, which involves insulin deficiency and high blood sugar.
Q70. Which of the following is correct? (i) Hypothalamic hormones are released from nerve endings. (ii) Pituitary gland is attached by a stalk. (iii) TCT regulates blood calcium.
Correct Answer: (a)
Hypothalamic neurosecretory cells release their hormones from axon terminals (nerve endings) into the portal circulation. The pituitary gland is attached to the hypothalamus by a stalk called the infundibulum. Thyrocalcitonin (TCT), produced by the thyroid, lowers blood calcium levels. Since all three statements accurately describe anatomical and physiological facts, the answer is that all are correct.
Q71. Which of the following organs is correctly matched with its non-endocrine hormone secretion? (i) Heart – ANF. (ii) Kidney – Erythropoietin. (iii) Liver – Bile juice (Bile is not a hormone). (iv) GI Tract – Gastrin.
Correct Answer: (a)
The heart secretes ANF, the kidney secretes erythropoietin, the GI tract secretes gastrin, and the liver produces bile (which is not a hormone). All statements are correct, including the note that bile is not a hormone.
Q72. Which hormone regulates the growth of mammary glands and formation of milk?
Correct Answer: (b)
Prolactin (PRL) is the primary hormone responsible for the development of mammary glands and the initiation and maintenance of milk production (lactogenesis). It is secreted by the anterior pituitary and its release is stimulated by suckling and other factors, while inhibited by dopamine from the hypothalamus.
Q73. Assertion: Melatonin influences the menstrual cycle.
Reason: It is secreted by the pineal gland.
Correct Answer: (b)
Melatonin does influence the menstrual cycle by modulating the hypothalamic‑pituitary‑gonadal axis, and it is indeed secreted by the pineal gland. However, the reason simply states the source of melatonin and does not explain how it affects the menstrual cycle. Both statements are true, but the reason does not provide a causal link, so it is not the correct explanation.
Q74. Assertion: The thymus gland is essential for the immune system of young individuals.
Reason: It helps in the differentiation of T-lymphocytes which provide cell-mediated immunity.
Correct Answer: (a)
The thymus is vital for the immune system, especially during early life, because it is the site of T‑lymphocyte maturation. These T cells are crucial for cell‑mediated immunity, which defends against intracellular pathogens and abnormal cells. The thymus also produces thymosins that promote T‑cell differentiation. Therefore, the reason accurately explains why the thymus is essential for the immune system of young individuals, making it the correct explanation.
Q75. Regarding the hormone Glucagon: (i) Secreted by alpha-cells. (ii) Stimulates glycogenolysis in hepatocytes. (iii) Reduces cellular glucose uptake. (iv) It is a hyperglycemic hormone.
Correct Answer: (a)
Glucagon is secreted by alpha‑cells; it stimulates glycogenolysis in the liver; it also tends to reduce glucose uptake in certain tissues (by counteracting insulin effects); and it is hyperglycemic. Thus all statements are correct.
Q76. Assertion: Gastrin stimulates the secretion of HCl.
Reason: It acts on the gastric glands of the stomach.
Correct Answer: (a)
Gastrin is a hormone released from the G‑cells of the stomach antrum. It stimulates the parietal cells of the gastric glands to secrete hydrochloric acid (HCl) and also promotes secretion of pepsinogen. The reason correctly identifies the target site (gastric glands) where gastrin exerts its action, thus explaining how it stimulates HCl secretion.
Q77. Glucagon is secreted by which cells of the Islets of Langerhans?
Correct Answer: (b)
Glucagon is produced by the alpha‑cells of the pancreatic islets (Islets of Langerhans). These cells are located in the periphery of the islets. Glucagon acts to increase blood glucose levels by stimulating glycogen breakdown and gluconeogenesis in the liver, thus counteracting the effects of insulin.
Q78. Match the hormones with their chemical nature:
Column-I (Hormone)
Column-II (Nature)
A. Insulin
(I) Steroid
B. Cortisol
(II) Peptide
C. Thyroxine
(III) Amino-acid derivative
D. Epinephrine
(IV) Iodothyronine
Correct Answer: (a)
Insulin is a peptide hormone (II); cortisol is a steroid (I); thyroxine is an iodothyronine (IV); and epinephrine is derived from amino acids (III). This classification is based on the chemical structure of each hormone.
Q79. Melatonin plays a very important role in the regulation of:
Correct Answer: (b)
Melatonin is the key hormone that maintains the body’s internal clock, known as the circadian rhythm. It is secreted in a daily cycle, with high levels at night and low levels during the day, helping to regulate sleep‑wake patterns, body temperature, and other physiological processes that follow a 24‑hour period.
Q80. Hormones which interact with intracellular receptors (e.g., steroid hormones) mostly regulate:
Correct Answer: (b)
Steroid hormones are lipophilic and can easily cross the cell membrane. Once inside the target cell, they bind to intracellular receptors (often in the cytoplasm or nucleus), and the hormone‑receptor complex then acts as a transcription factor. This directly influences gene expression, leading to the synthesis of specific proteins that produce the physiological response.
Q81. Choose the correct statements regarding the hormone action mechanism: (i) Hormone-receptor complex formation leads to biochemical changes. (ii) Protein hormones interact with membrane-bound receptors. (iii) Steroid hormones interact with intracellular receptors. (iv) Receptors are specific to one hormone only.
Correct Answer: (a)
All these statements are true. Hormone‑receptor complexes initiate cellular responses; protein hormones use membrane receptors; steroid hormones use intracellular receptors; and receptors exhibit high specificity for their ligands.
Q82. Assertion: Hypothalamus is the master regulator of the endocrine system.
Reason: It produces releasing and inhibiting hormones that regulate the pituitary gland.
Correct Answer: (a)
The hypothalamus is often called the master regulator because it controls the pituitary gland, which in turn governs many other endocrine glands. By secreting releasing and inhibiting hormones into the pituitary portal system, the hypothalamus can stimulate or suppress the release of pituitary hormones. This hierarchical control allows the hypothalamus to integrate neural and hormonal signals, making it the highest centre of the endocrine system. Thus, the reason correctly explains why the hypothalamus is considered the master regulator.
Q83. Assertion: Graves' disease is characterized by weight loss.
Reason: It is a form of hyperthyroidism which increases the basal metabolic rate.
Correct Answer: (a)
Graves’ disease is an autoimmune condition causing hyperthyroidism, where thyroid hormones are overproduced. This excess elevates the basal metabolic rate, leading to increased energy expenditure and consequent weight loss. The reason correctly explains the physiological mechanism behind weight loss in Graves’ disease, making it the correct explanation.
Q84. Assertion: ANF decreases blood pressure.
Reason: It causes vasodilation of blood vessels.
Correct Answer: (a)
Atrial Natriuretic Factor (ANF) lowers blood pressure through multiple mechanisms, including vasodilation. By relaxing vascular smooth muscle, ANF reduces peripheral resistance, and also promotes sodium and water excretion, reducing blood volume. The reason correctly identifies vasodilation as a key action that contributes to the blood‑pressure‑lowering effect, making it the correct explanation for the assertion.
Q85. Assertion: Pituitary dwarfism is caused by low secretion of GH.
Reason: GH stimulates abnormal growth of the body.
Correct Answer: (c)
Pituitary dwarfism is indeed caused by insufficient growth hormone during childhood, resulting in stunted growth. However, the reason states that GH stimulates abnormal growth, which is incorrect—GH promotes normal growth. Abnormal growth (gigantism or acromegaly) is due to GH over‑secretion, not its normal action. Therefore, the assertion is true but the reason is false.
Q86. Insulin acts mainly on hepatocytes and ______ to enhance glucose uptake.
Correct Answer: (b)
Insulin promotes glucose uptake primarily in hepatocytes (liver cells) and adipocytes (fat cells). It does this by stimulating the translocation of glucose transporter proteins (GLUT4) to the cell membrane. In muscle cells, insulin also facilitates glucose uptake, but the question specifically mentions hepatocytes and adipocytes.
Q87. Match the disorders with their descriptions:
Column-I (Disorder)
Column-II (Description)
A. Diabetes Insipidus
(I) ADH deficiency
B. Diabetes Mellitus
(II) Insulin deficiency / resistance
C. Graves' Disease
(III) Hyperthyroidism
D. Addison's Disease
(IV) Adrenal cortex underproduction
Correct Answer: (a)
Diabetes insipidus is due to ADH deficiency (I); diabetes mellitus results from insulin deficiency or resistance (II); Graves' disease is a form of hyperthyroidism (III); and Addison's disease is caused by adrenal cortex underproduction (IV). These definitions are standard for each disorder.
Q88. Assertion: Glucagon is a hyperglycemic hormone.
Reason: It stimulates glycogenolysis and gluconeogenesis, increasing blood sugar.
Correct Answer: (a)
Glucagon acts on the liver to promote glycogenolysis (breakdown of glycogen to glucose) and gluconeogenesis (synthesis of glucose from non‑carbohydrate precursors). These processes raise the concentration of glucose in the blood, which is why glucagon is classified as a hyperglycemic hormone. The reason correctly describes the biochemical mechanisms that underpin the hyperglycemic effect, thus providing a valid explanation for the assertion.
Q89. Match the GI tract hormones with their primary actions:
Column-I (Hormone)
Column-II (Action)
A. Gastrin
(I) Secretion of HCl
B. Secretin
(II) Water and bicarbonate secretion
C. CCK
(III) Pancreatic enzyme release
D. GIP
(IV) Inhibits gastric secretion
Correct Answer: (a)
Gastrin stimulates HCl secretion (I); secretin promotes water and bicarbonate release from pancreas (II); CCK stimulates pancreatic enzyme release (III); and GIP inhibits gastric secretion (IV). These are the classical actions of these gastrointestinal hormones.
Q90. The main mineralocorticoid in our body is:
Correct Answer: (c)
Aldosterone is the principal mineralocorticoid produced by the adrenal cortex. It acts on the distal tubules and collecting ducts of the kidney to promote the reabsorption of sodium ions and the excretion of potassium ions, thereby regulating blood volume and electrolyte balance. Its secretion is stimulated by angiotensin II and low blood sodium levels.
Q91. Select correct statements for the mechanism of protein hormone action: (i) Binding to membrane receptor. (ii) Generation of second messenger like cAMP. (iii) Modification of gene expression directly.
Correct Answer: (a)
Protein hormones bind to membrane receptors and generate second messengers (e.g., cAMP). They do not directly modify gene expression; that is typical of steroid hormones. Thus only (i) and (ii) are correct.
Q92. Match the following for metabolic effects:
Term
Meaning
A. Glycogenolysis
(I) Breakdown of glycogen
B. Gluconeogenesis
(II) Formation of glucose from non-carbs
C. Glycogenesis
(III) Conversion of glucose to glycogen
Correct Answer: (a)
Glycogenolysis is the breakdown of glycogen (I); gluconeogenesis is the synthesis of glucose from non‑carbohydrate sources (II); and glycogenesis is the conversion of glucose to glycogen (III). These definitions are standard metabolic terminology.
Q93. Match the hormone with its specific effect:
Column-I
Column-II
A. Oxytocin
(I) Vigorous contraction of uterus
B. Vasopressin
(II) Resorption of water by distal tubules
C. Melatonin
(III) Diurnal rhythm
D. Thymosin
(IV) Differentiation of T-lymphocytes
Correct Answer: (a)
Oxytocin causes uterine contractions (I); vasopressin (ADH) promotes water reabsorption in the distal tubules (II); melatonin regulates the diurnal rhythm (III); and thymosins assist in T‑lymphocyte differentiation (IV). This matching is based on their primary physiological functions.
Q94. Oxytocin and Vasopressin are actually synthesized by the:
Correct Answer: (c)
Although these hormones are stored and released from the posterior pituitary, they are synthesized in the hypothalamus. Oxytocin and vasopressin (ADH) are produced in the supraoptic and paraventricular nuclei of the hypothalamus, then transported along axons to the posterior pituitary where they are stored in secretory vesicles.
Q95. Assertion: The posterior pituitary is also known as neurohypophysis.
Reason: It is under the direct neural regulation of the hypothalamus.
Correct Answer: (a)
The posterior pituitary is called the neurohypophysis because it is composed of neural tissue and is directly connected to the hypothalamus via nerve fibres. Its hormones are synthesized in hypothalamic neurons and transported down the axons for storage and release. This direct neural regulation is the reason it is named neurohypophysis, so the reason correctly explains the assertion.
Q96. Assertion: Hormone receptors are specific.
Reason: Each receptor is specific to one hormone only.
Correct Answer: (a)
Receptors for hormones exhibit high specificity, meaning that a given receptor typically binds only one type of hormone (or a limited class). This specificity ensures that only the target cells respond to a particular hormone, allowing precise regulation. The reason correctly explains the concept of specificity, making it the correct explanation for the assertion.
Q97. Select the correct statements for Thyroid hormones: (i) Synthesis requires iodine. (ii) They regulate the basal metabolic rate. (iii) They support RBC formation. (iv) They maintain water and electrolyte balance.
Correct Answer: (a)
Thyroid hormones require iodine for synthesis, regulate BMR, support erythropoiesis, and also influence water and electrolyte balance. All four statements are true, reflecting the wide‑ranging effects of thyroid hormones.
Q98. Assertion: The neural coordination is fast but short-lived.
Reason: Hormones provide continuous regulation for cellular functions not innervated by nerve fibres.
Correct Answer: (b)
Neural signals travel rapidly along nerves and produce immediate responses, but these effects are usually brief because the nervous system quickly adapts. Hormonal coordination, on the other hand, is slower but provides sustained regulation, especially for tissues that lack nerve supply. However, the reason does not explain why neural coordination is short‑lived; it simply describes the role of hormones. Therefore, both statements are true, but the reason is not the correct explanation for the assertion.
Q99. Regarding the Thyroid gland structure: (i) Composed of follicles and stromal tissues. (ii) Each follicle is composed of follicular cells. (iii) Follicles enclose a cavity.
Correct Answer: (a)
The thyroid is made up of follicles containing colloid in a central cavity; the follicles are lined by follicular cells. All three statements correctly describe the histological structure of the thyroid gland.
Q100. Erythropoietin, which stimulates RBC formation, is produced by:
Correct Answer: (c)
Erythropoietin (EPO) is primarily produced by the juxtaglomerular cells of the kidney. In response to low oxygen levels (hypoxia), these cells increase EPO secretion, which stimulates the bone marrow to produce more red blood cells. EPO is essential for maintaining adequate oxygen‑carrying capacity of the blood.