NCERT NEET Biology English Medium Part-1 | Chapter 19 : Chemical Coordination and Integration.

NCERT NEET Biology English Medium Part-1 | Chapter 19 : Chemical Coordination and Integration.

Question 1: Which of the following is an incorrect statement regarding the neural coordination in the human body?

It provides point-to-point rapid coordination among organs.
The neural coordination is fast but short-lived.
Nerve fibres innervate all the cells of the body continuously.
It jointly coordinates with the endocrine system to regulate physiological functions.

Answer: c. Nerve fibres innervate all the cells of the body continuously.

Question 2: According to the current scientific definition, hormones are characterised by all of the following, except?

They are non-nutrient chemicals.
They act as intercellular messengers.
They are produced in large quantities.
They include molecules secreted by unorganised endocrine tissues.

Answer: c. They are produced in large quantities.

Question 3: Invertebrates differ from vertebrates in their endocrine system because invertebrates possess?

Complex endocrine systems with many hormones.
Very simple endocrine systems with few hormones.
Only neural coordination and no endocrine system.
Hormones that act as intracellular messengers only.

Answer: b. Very simple endocrine systems with few hormones.

Question 4: Which of the following organs does not contain hormone-producing diffused tissues or cells?

Gastrointestinal tract.
Liver.
Heart.
Gall bladder.

Answer: d. Gall bladder.

Question 5: The hypothalamus is anatomically located in which part of the brain?

Basal part of the diencephalon in the forebrain.
Dorsal part of the midbrain.
Ventral part of the hindbrain.
Lateral part of the cerebrum.

Answer: a. Basal part of the diencephalon in the forebrain.

Question 6: The neurosecretory cells present in the hypothalamus that produce hormones are specifically called?

Ganglia.
Tracts.
Nuclei.
Nissl bodies.

Answer: c. Nuclei.

Question 7: Somatostatin from the hypothalamus has which of the following effects on the pituitary gland?

It stimulates the release of growth hormone.
It inhibits the release of growth hormone.
It stimulates the release of gonadotrophins.
It inhibits the release of prolactin.

Answer: b. It inhibits the release of growth hormone.

Question 8: The hormones from the hypothalamus reach the anterior pituitary through which specific pathway?

Direct neural regulation via axons.
A portal circulatory system.
The lymphatic system.
The cerebrospinal fluid.

Answer: b. A portal circulatory system.

Question 9: Which part of the pituitary is under the direct neural regulation of the hypothalamus?

Pars distalis.
Pars intermedia.
Posterior pituitary.
Adenohypophysis.

Answer: c. Posterior pituitary.

Question 10: The bony cavity in which the pituitary gland is located is called?

Foramen magnum.
Sella tursica.
Acetabulum.
Glenoid cavity.

Answer: b. Sella tursica.

Question 11: Anatomically, the pituitary gland is divided into which two main parts?

Pars distalis and pars intermedia.
Adenohypophysis and neurohypophysis.
Anterior pituitary and posterior pituitary.
Hypothalamus and infundibulum.

Answer: b. Adenohypophysis and neurohypophysis.

Question 12: In humans, the pars intermedia is almost completely merged with which of the following structures?

Pars nervosa.
Hypothalamus.
Pars distalis.
Pineal gland.

Answer: c. Pars distalis.

Question 13: Which of the following hormones is not secreted by the pars distalis region of the pituitary?

Prolactin (PRL).
Adrenocorticotrophic hormone (ACTH).
Melanocyte stimulating hormone (MSH).
Luteinizing hormone (LH).

Answer: c. Melanocyte stimulating hormone (MSH).

Question 14: Oxytocin and vasopressin are stored and released by the neurohypophysis, but they are actually synthesised in the?

Pars nervosa.
Pars distalis.
Hypothalamus.
Pineal gland.

Answer: c. Hypothalamus.

Question 15: Severe disfigurement of the face in adults, especially in middle age, caused by excess secretion of growth hormone is called?

Gigantism.
Pituitary dwarfism.
Acromegaly.
Exopthalmic goitre.

Answer: c. Acromegaly.

Question 16: Which of the following statements about Acromegaly is true based on NCERT?

It is easily diagnosed in its early stages.
It leads to premature death if left unchecked.
It is caused by low secretion of growth hormone.
It primarily affects the limbs and spares the face.

Answer: b. It leads to premature death if left unchecked.

Question 17: Which hormone stimulates the synthesis and secretion of steroid hormones called glucocorticoids?

Thyroid stimulating hormone (TSH).
Adrenocorticotrophic hormone (ACTH).
Luteinizing hormone (LH).
Follicle stimulating hormone (FSH).

Answer: b. Adrenocorticotrophic hormone (ACTH).

Question 18: In human males, which hormone directly stimulates the synthesis and secretion of androgens from the testis?

FSH.
LH.
ACTH.
PRL.

Answer: b. LH.

Question 19: Which two hormones jointly regulate spermatogenesis in human males?

LH and FSH.
FSH and androgens.
LH and androgens.
FSH and testosterone only.

Answer: b. FSH and androgens.

Question 20: The hormone responsible for inducing ovulation of fully mature Graafian follicles in females is?

FSH.
Progesterone.
Estrogen.
LH.

Answer: d. LH.

Question 21: Which hormone maintains the corpus luteum formed from the remnants of the Graafian follicles after ovulation?

Luteinizing hormone (LH).
Follicle stimulating hormone (FSH).
Prolactin (PRL).
Oxytocin.

Answer: a. Luteinizing hormone (LH).

Question 22: Melanocyte stimulating hormone (MSH), which regulates the pigmentation of the skin, acts on?

Keratinocytes.
Melanocytes.
Adipocytes.
Fibroblasts.

Answer: b. Melanocytes.

Question 23: Oxytocin exerts its physiological actions primarily on which type of tissues in the human body?

Skeletal muscles.
Cardiac muscles.
Smooth muscles.
Connective tissues.

Answer: c. Smooth muscles.

Question 24: Milk ejection from the mammary glands is directly stimulated by which of the following hormones?

Prolactin.
Estrogen.
Progesterone.
Oxytocin.

Answer: d. Oxytocin.

Question 25: Vasopressin mainly acts at the kidney and stimulates the resorption of water and electrolytes by the?

Proximal convoluted tubule.
Loop of Henle.
Distal tubules.
Bowman's capsule.

Answer: c. Distal tubules.

Question 26: A diminished ability of the kidney to conserve water, leading to water loss and dehydration, is known as?

Diabetes mellitus.
Diabetes insipidus.
Addison's disease.
Graves' disease.

Answer: b. Diabetes insipidus.

Question 27: The pineal gland is anatomically located on the?

Ventral side of the forebrain.
Dorsal side of the forebrain.
Dorsal side of the midbrain.
Ventral side of the hindbrain.

Answer: b. Dorsal side of the forebrain.

Question 28: Melatonin, secreted by the pineal gland, plays a crucial role in maintaining all of the following, except?

Normal rhythms of sleep-wake cycle.
Body temperature.
Blood calcium levels.
Menstrual cycle and defense capability.

Answer: c. Blood calcium levels.

Question 29: The two lobes of the thyroid gland are interconnected with a thin flap of connective tissue called the?

Infundibulum.
Isthmus.
Corpus callosum.
Macula densa.

Answer: b. Isthmus.

Question 30: Each thyroid follicle is composed of follicular cells enclosing a cavity. These cells synthesise which of the following hormones?

T3 and T4.
Thyrocalcitonin and PTH.
Melatonin and Thymosin.
Cortisol and Aldosterone.

Answer: a. T3 and T4.

Question 31: Hypothyroidism during pregnancy causes defective development of the growing baby. This condition is characterised by?

Acromegaly.
Gigantism.
Cretinism.
Diabetes insipidus.

Answer: c. Cretinism.

Question 32: Which of the following is not a symptom of cretinism in a growing baby?

Mental retardation.
High intelligence quotient.
Abnormal skin.
Deaf-mutism.

Answer: b. High intelligence quotient.

Question 33: In adult women, an irregular menstrual cycle can be a direct consequence of?

Hyperparathyroidism.
Hypothyroidism.
Diabetes insipidus.
Addison's disease.

Answer: b. Hypothyroidism.

Question 34: Graves' disease is a form of hyperthyroidism characterised by all of the following, except?

Enlargement of the thyroid gland.
Protrusion of the eyeballs.
Decreased basal metabolic rate.
Weight loss.

Answer: c. Decreased basal metabolic rate.

Question 35: Which of the following endocrine glands secretes a protein hormone that regulates blood calcium levels?

Pineal gland.
Adrenal medulla.
Thyroid gland.
Thymus.

Answer: c. Thyroid gland.

Question 36: The hormone thyrocalcitonin (TCT) acts to?

Increase blood calcium levels.
Decrease blood calcium levels.
Increase blood glucose levels.
Decrease blood glucose levels.

Answer: b. Decrease blood calcium levels.

Question 37: In humans, how many parathyroid glands are present, and where are they located?

Two, on the ventral side of the thyroid gland.
Four, on the back side of the thyroid gland.
Two, embedded within the thymus.
Four, located above the kidneys.

Answer: b. Four, on the back side of the thyroid gland.

Question 38: The secretion of parathyroid hormone (PTH) is primarily regulated by the circulating levels of?

Sodium ions.
Potassium ions.
Calcium ions.
Phosphate ions.

Answer: c. Calcium ions.

Question 39: Parathyroid hormone (PTH) increases blood Ca2+ levels by stimulating which of the following processes in bones?

Bone formation.
Bone resorption (demineralisation).
Bone calcification.
Collagen synthesis.

Answer: b. Bone resorption (demineralisation).

Question 40: Which two hormones play a significant synergistic and antagonistic role in maintaining the calcium balance in the human body?

PTH and Aldosterone.
TCT and PTH.
T3 and T4.
Glucocorticoids and Mineralocorticoids.

Answer: b. TCT and PTH.

Question 41: The thymus gland is a lobular structure located?

Above the kidneys on the dorsal side.
Between the lungs behind the sternum on the ventral side of the aorta.
On the dorsal side of the forebrain.
On either side of the trachea.

Answer: b. Between the lungs behind the sternum on the ventral side of the aorta.

Question 42: Thymosins play a major role in the differentiation of T-lymphocytes, which primarily provide?

Humoral immunity.
Cell-mediated immunity.
Innate immunity.
Autoimmunity.

Answer: b. Cell-mediated immunity.

Question 43: In addition to cell-mediated immunity, thymosins also promote the production of antibodies to provide?

Phagocytic immunity.
Humoral immunity.
Passive immunity.
Inflammatory responses.

Answer: b. Humoral immunity.

Question 44: The immune responses of older individuals become weak primarily due to?

Hyperactivity of the thymus gland.
Degeneration of the thymus leading to decreased production of thymosins.
Overproduction of bone marrow stem cells.
Increased secretion of cortisol by the adrenal gland.

Answer: b. Degeneration of the thymus leading to decreased production of thymosins.

Question 45: The centrally located tissue of the adrenal gland is called the?

Adrenal cortex.
Adrenal medulla.
Zona glomerulosa.
Zona reticularis.

Answer: b. Adrenal medulla.

Question 46: Underproduction of hormones by the adrenal cortex alters carbohydrate metabolism, causing acute weakness and fatigue. This disease is known as?

Cushing's syndrome.
Addison's disease.
Graves' disease.
Hashimoto's disease.

Answer: b. Addison's disease.

Question 47: Adrenaline and noradrenaline, secreted by the adrenal medulla, are commonly called?

Glucocorticoids.
Mineralocorticoids.
Catecholamines.
Androgens.

Answer: c. Catecholamines.

Question 48: The "hormones of Fight or Flight" cause all of the following physiological responses, except?

Increased alertness and pupilary dilation.
Piloerection and sweating.
Decreased heart beat and rate of respiration.
Increased strength of heart contraction.

Answer: c. Decreased heart beat and rate of respiration.

Question 49: Catecholamines stimulate the breakdown of which stored compound, resulting in an increased concentration of glucose in the blood?

Starch.
Glycogen.
Cellulose.
Cholesterol.

Answer: b. Glycogen.

Question 50: The inner, middle, and outer layers of the adrenal cortex are respectively known as?

Zona glomerulosa, zona fasciculata, zona reticularis.
Zona reticularis, zona fasciculata, zona glomerulosa.
Zona fasciculata, zona reticularis, zona glomerulosa.
Zona reticularis, zona glomerulosa, zona fasciculata.

Answer: b. Zona reticularis, zona fasciculata, zona glomerulosa.

Question 51: The corticoids that are primarily involved in carbohydrate metabolism are termed?

Mineralocorticoids.
Glucocorticoids.
Catecholamines.
Sex corticoids.

Answer: b. Glucocorticoids.

Question 52: Which of the following is the main glucocorticoid found in the human body?

Aldosterone.
Testosterone.
Cortisol.
Estradiol.

Answer: c. Cortisol.

Question 53: Glucocorticoids stimulate all of the following metabolic processes, except?

Gluconeogenesis.
Lipolysis.
Proteolysis.
Cellular uptake and utilisation of amino acids.

Answer: d. Cellular uptake and utilisation of amino acids.

Question 54: Which specific hormone produces anti-inflammatory reactions and suppresses the immune response?

Aldosterone.
Cortisol.
Thyroxine.
Melatonin.

Answer: b. Cortisol.

Question 55: Aldosterone, the main mineralocorticoid, acts mainly at the renal tubules and stimulates the reabsorption of?

K+ and phosphate ions.
Na+ and water.
Glucose and amino acids.
Urea and uric acid.

Answer: b. Na+ and water.

Question 56: The excretion of which specific ions is stimulated by the action of aldosterone on the renal tubules?

Na+ and Cl-.
K+ and phosphate ions.
Ca2+ and Mg2+.
HCO3- and H+.

Answer: b. K+ and phosphate ions.

Question 57: Small amounts of androgenic steroids are also secreted by the adrenal cortex. They play a role in the growth of?

Axial hair, pubic hair, and facial hair during puberty.
Mammary glands in females.
Thyroid follicles.
Ovarian follicles.

Answer: a. Axial hair, pubic hair, and facial hair during puberty.

Question 58: The pancreas acts as a composite gland because it has?

Only exocrine tissues.
Only endocrine tissues.
Both exocrine and endocrine tissues.
Multiple lobes that produce different hormones.

Answer: c. Both exocrine and endocrine tissues.

Question 59: The endocrine pancreas consists of clusters of cells called the?

Acini.
Islets of Langerhans.
Kupffer cells.
Chief cells.

Answer: b. Islets of Langerhans.

Question 60: In a normal human pancreas, approximately how many Islets of Langerhans are present?

1 to 2 thousand.
1 to 2 million.
10 to 20 million.
1 to 2 billion.

Answer: b. 1 to 2 million.

Question 61: The alpha cells and beta cells of the Islets of Langerhans respectively secrete?

Insulin and Glucagon.
Glucagon and Insulin.
Somatostatin and Pancreatic Polypeptide.
Glucagon and Somatostatin.

Answer: b. Glucagon and Insulin.

Question 62: Glucagon acts primarily on hepatocytes and stimulates which process, resulting in an increased blood sugar level?

Glycogenesis.
Glycogenolysis.
Lipogenesis.
Protein synthesis.

Answer: b. Glycogenolysis.

Question 63: Glucagon is considered a hyperglycemic hormone because it?

Increases cellular glucose uptake.
Stimulates gluconeogenesis.
Inhibits glycogenolysis.
Stimulates the conversion of glucose to glycogen.

Answer: b. Stimulates gluconeogenesis.

Question 64: Insulin is a peptide hormone that primarily regulates glucose homeostasis by acting on?

Hepatocytes and adipocytes.
Osteocytes and chondrocytes.
Neurons and glial cells.
Erythrocytes and leukocytes.

Answer: a. Hepatocytes and adipocytes.

Question 65: The rapid movement of glucose from the blood to hepatocytes and adipocytes under the influence of insulin results in?

Hyperglycemia.
Hypoglycemia.
Glycosuria.
Gluconeogenesis.

Answer: b. Hypoglycemia.

Question 66: The conversion of glucose to glycogen in the target cells stimulated by insulin is termed?

Glycogenolysis.
Glycogenesis.
Gluconeogenesis.
Lipolysis.

Answer: b. Glycogenesis.

Question 67: Prolonged hyperglycemia leads to a complex disorder known as?

Diabetes insipidus.
Diabetes mellitus.
Addison's disease.
Acromegaly.

Answer: b. Diabetes mellitus.

Question 68: Diabetes mellitus is characteristically associated with loss of glucose through urine and formation of harmful compounds known as?

Ketone bodies.
Urea crystals.
Uric acid crystals.
Ammonium salts.

Answer: a. Ketone bodies.

Question 69: The Leydig cells or interstitial cells, which produce androgens, are located in the?

Seminiferous tubules.
Intertubular spaces of the testis.
Epididymis.
Vas deferens.

Answer: b. Intertubular spaces of the testis.

Question 70: Which of the following is not a primary function of androgens in human males?

Stimulate the maturation of epididymis and vas deferens.
Stimulate muscular growth and facial/axillary hair growth.
Inhibit the process of spermatogenesis.
Act on the central neural system and influence male sexual behaviour.

Answer: c. Inhibit the process of spermatogenesis.

Question 71: Androgens produce an anabolic (synthetic) effect on which two components of metabolism?

Protein and carbohydrate.
Lipid and vitamin.
Carbohydrate and mineral.
Protein and lipid.

Answer: a. Protein and carbohydrate.

Question 72: After ovulation, the ruptured follicle is converted to a structure called the corpus luteum, which mainly secretes?

Estrogen.
Progesterone.
LH.
FSH.

Answer: b. Progesterone.

Question 73: Estrogen in females is synthesised and secreted primarily by the?

Corpus luteum.
Growing ovarian follicles.
Uterine endometrium.
Fallopian tubes.

Answer: b. Growing ovarian follicles.

Question 74: Which hormone specifically acts on the mammary glands to stimulate the formation of alveoli (sac-like structures that store milk) and milk secretion?

Estrogen.
Progesterone.
Oxytocin.
Relaxin.

Answer: b. Progesterone.

Question 75: The atrial wall of our heart secretes a very important peptide hormone known as Atrial Natriuretic Factor (ANF). What is its primary function?

It increases blood pressure.
It decreases blood pressure.
It increases heart rate.
It stimulates the release of renin.

Answer: b. It decreases blood pressure.

Question 76: When blood pressure is increased, ANF is secreted, causing?

Constriction of blood vessels.
Dilation of blood vessels.
Increased sodium reabsorption.
Increased water retention.

Answer: b. Dilation of blood vessels.

Question 77: The juxtaglomerular cells (JG cells) of the kidney produce a peptide hormone called erythropoietin, which stimulates?

Erythropoiesis (formation of RBCs).
Leukopoiesis (formation of WBCs).
Thrombopoiesis (formation of platelets).
Gluconeogenesis.

Answer: a. Erythropoiesis (formation of RBCs).

Question 78: In the gastrointestinal tract, the hormone Gastrin acts primarily on the?

Pancreas.
Gall bladder.
Gastric glands.
Intestinal mucosa.

Answer: c. Gastric glands.

Question 79: Gastrin stimulates the secretion of which two substances?

Pepsinogen and intrinsic factor.
Hydrochloric acid and pepsinogen.
Bile and pancreatic juice.
Mucus and bicarbonate.

Answer: b. Hydrochloric acid and pepsinogen.

Question 80: Secretin acts on the exocrine pancreas and stimulates the secretion of?

Water and bicarbonate ions.
Pancreatic enzymes.
Insulin and glucagon.
Trypsinogen.

Answer: a. Water and bicarbonate ions.

Question 81: Cholecystokinin (CCK) stimulates the secretion of pancreatic enzymes and bile juice by acting on which two target organs respectively?

Pancreas and stomach.
Pancreas and gall bladder.
Liver and gall bladder.
Stomach and liver.

Answer: b. Pancreas and gall bladder.

Question 82: Gastric inhibitory peptide (GIP) functions to?

Stimulate gastric secretion and motility.
Inhibit gastric secretion and motility.
Stimulate intestinal motility.
Inhibit bile secretion.

Answer: b. Inhibit gastric secretion and motility.

Question 83: Hormones produce their effects on target tissues by binding to specific proteins known as?

Antigens.
Hormone receptors.
Enzymes.
Carrier proteins.

Answer: b. Hormone receptors.

Question 84: Receptors present on the cell membrane of target cells are called?

Intracellular receptors.
Membrane-bound receptors.
Nuclear receptors.
Cytoplasmic receptors.

Answer: b. Membrane-bound receptors.

Question 85: Receptors present inside the target cell are predominantly?

Membrane-bound receptors.
Nuclear receptors.
Extracellular receptors.
Interstitial receptors.

Answer: b. Nuclear receptors.

Question 86: Binding of a hormone to its receptor always leads to the formation of a?

Hormone-enzyme complex.
Hormone-receptor complex.
Protein-lipid complex.
Primary messenger complex.

Answer: b. Hormone-receptor complex.

Question 87: Hormones which interact with membrane-bound receptors normally?

Enter the target cell.
Do not enter the target cell.
Directly interact with the genome.
Alter gene expression directly.

Answer: b. Do not enter the target cell.

Question 88: Hormones that bind to membrane-bound receptors generate second messengers. Which of the following is not a common second messenger?

Cyclic AMP (cAMP).
IP3.
Ca2+.
ATP.

Answer: d. ATP.

Question 89: Which class of hormones mostly interacts with intracellular receptors?

Peptide hormones.
Protein hormones.
Steroid hormones and iodothyronines.
Amino-acid derivatives like epinephrine.

Answer: c. Steroid hormones and iodothyronines.

Question 90: The hormone-receptor complex formed inside the target cell regulates gene expression or chromosome function by interacting with?

The cell membrane.
The genome.
The mitochondria.
The Golgi apparatus.

Answer: b. The genome.

Question 91: Which of the following is an example of an amino-acid derivative hormone?

Epinephrine.
Cortisol.
Insulin.
Estradiol.

Answer: a. Epinephrine.

Question 92: Based on chemical nature, glucagon belongs to which group of hormones?

Steroids.
Peptide, polypeptide, protein hormones.
Iodothyronines.
Amino-acid derivatives.

Answer: b. Peptide, polypeptide, protein hormones.

Question 93: Match the following columns and select the correct option.

Column I (Hormone)

FSH
Cortisol
Epinephrine

Column II (Chemical Nature)

Steroid
Amino acid derivative
Protein/Glycoprotein
A-3, B-1, C-2.
A-1, B-2, C-3.
A-2, B-3, C-1.
A-3, B-2, C-1.

Answer: a. A-3, B-1, C-2.

Question 94: Assertion: Insulin and glucagon maintain glucose homeostasis in the blood.

Reason: They act antagonistically; insulin is hypoglycemic while glucagon is hyperglycemic.

Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
Assertion is true, but Reason is false.
Both Assertion and Reason are false.

Answer: a. Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.

Question 95: Statement I: The pars intermedia is almost merged with pars distalis in humans.

Statement II: Pars intermedia secretes Melanocyte Stimulating Hormone (MSH).

Both Statement I and Statement II are incorrect.
Statement I is correct but Statement II is incorrect.
Statement I is incorrect but Statement II is correct.
Both Statement I and Statement II are correct.

Answer: d. Both Statement I and Statement II are correct.

Question 96: Which specific nucleus/nuclei of the hypothalamus produce oxytocin and vasopressin?

Neurosecretory cells.
Glial cells.
Astrocytes.
Schwann cells.

Answer: a. Neurosecretory cells.

Question 97: Assertion: Thyroid hormones promote the basal metabolic rate.

Reason: They regulate the metabolism of carbohydrates, proteins, and fats.

Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
Assertion is true, but Reason is false.
Both Assertion and Reason are false.

Answer: a. Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.

Question 98: Statement I: Parathyroid hormone (PTH) plays a significant role in calcium balance along with TCT.

Statement II: PTH increases renal reabsorption of calcium and stimulates bone resorption.