Biology MCQ, Class-11th, Chapter-19, Chemical Coordination and Integration

NCERT based Biology MCQ of Class 11th, Chapter-2, Chemical Coordination and Integration with brief explanation for competitive exams like TGT HTET, KVS PGT, SSC and all other state competition exams.

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12th Biology MCQ PDF - NCERT Based

NCERT Based MCQ with Explanation:

1. What is the primary function of hormones?

(a) Provide rapid, point-to-point communication

(b) Regulate physiological functions continuously

(c) Stimulate only neural pathways

(d) None of the above

Explanation: Hormones provide continuous regulation of cellular functions, complementing the neural system which offers rapid but short-lived coordination.

2. Which of the following is true about endocrine glands?

(a) They have ducts

(b) They are ductless glands

(c) They secrete digestive enzymes

(d) They work faster than the neural system

Explanation: Endocrine glands lack ducts and release hormones directly into the bloodstream.

NCERT MCQ, Biology Class-12th

3. The hypothalamus regulates the pituitary gland by producing:

(a) Digestive enzymes

(b) Releasing and inhibiting hormones

(c) Neurotransmitters

(d) Steroid hormones

Explanation: The hypothalamus produces releasing and inhibiting hormones that control the secretion of hormones from the anterior pituitary.

4. Which hormone is responsible for stimulating the release of growth hormone (GH)?

(a) Prolactin

(b) Gonadotropin-releasing hormone (GnRH)

(c) Growth hormone-releasing hormone (GHRH)

(d) Thyrotropin-releasing hormone (TRH)

Explanation: GHRH from the hypothalamus stimulates the release of GH from the anterior pituitary.

5. What is the primary function of vasopressin?

(a) Induce sleep

(b) Stimulate milk production

(c) Reduce water loss through urine

(d) Regulate blood sugar levels

Explanation: Vasopressin, also known as ADH, increases water reabsorption in the kidneys, reducing urine output.

6. Which gland secretes melatonin?

(a) Pituitary gland

(b) Pineal gland

(c) Thyroid gland

(d) Adrenal gland

Explanation: The pineal gland secretes melatonin, which regulates sleep-wake cycles and other diurnal rhythms.

7. Which hormone is known as the "emergency hormone"?

(a) Insulin

(b) Adrenaline

(c) Thyroxine

(d) Progesterone

Explanation: Adrenaline, secreted by the adrenal medulla, prepares the body for 'fight or flight' during emergencies.

8. The deficiency of which hormone causes goiter?

(a) Insulin

(b) Thyroxine

(c) Parathyroid hormone

(d) Cortisol

Explanation: A lack of iodine leads to hypothyroidism and goiter due to reduced thyroxine production.

9. What is the main function of oxytocin?

(a) Milk ejection and uterine contraction

(b) Increase blood sugar

(c) Stimulate growth hormone

(d) None of the above

Explanation: Oxytocin stimulates uterine contractions during childbirth and milk ejection during breastfeeding.

10. Which hormone helps regulate blood calcium levels?

(a) Insulin

(b) Parathyroid hormone (PTH)

(c) Vasopressin

(d) Melatonin

Explanation: PTH increases blood calcium levels by acting on bones, kidneys, and intestines.

11. The anterior pituitary is also known as:

(a) Pars nervosa

(b) Adenohypophysis

(c) Neurohypophysis

(d) Corpus luteum

Explanation: The anterior pituitary is anatomically referred to as adenohypophysis and is responsible for producing several trophic hormones.

12. The hormone that stimulates the secretion of glucocorticoids from the adrenal cortex is:

(a) Thyroid Stimulating Hormone (TSH)

(b) Adrenocorticotropic Hormone (ACTH)

(c) Follicle Stimulating Hormone (FSH)

(d) Growth Hormone (GH)

Explanation: ACTH stimulates the adrenal cortex to produce glucocorticoids like cortisol.

13. Which hormone influences the sleep-wake cycle?

(a) Thyroxine

(b) Cortisol

(c) Melatonin

(d) Prolactin

Explanation: Melatonin, secreted by the pineal gland, regulates the sleep-wake cycle and other diurnal rhythms.

14. The thyroid hormone triiodothyronine is also known as:

(a) T4

(b) T3

(c) TSH

(d) TCT

Explanation: Triiodothyronine is one of the primary thyroid hormones and is denoted as T3.

15. A deficiency of growth hormone (GH) in childhood results in:

(a) Acromegaly

(b) Gigantism

(c) Pituitary dwarfism

(d) Addison’s disease

Explanation: Insufficient GH secretion during childhood leads to stunted growth, known as pituitary dwarfism.

Biology MCQ, Class-12, Chapter-10, Biotechnology and Its Applications

16. Which hormone reduces blood pressure by causing vasodilation?

(a) Cortisol

(b) Atrial Natriuretic Factor (ANF)

(c) Vasopressin

(d) Aldosterone

Explanation: ANF, secreted by the heart, lowers blood pressure by promoting vasodilation.

17. The adrenal cortex secretes:

(a) Adrenaline

(b) Melatonin

(c) Corticoids

(d) Thyroxine

Explanation: The adrenal cortex produces glucocorticoids and mineralocorticoids, essential for metabolism and water balance.

18. Which hormone inhibits gastric secretion and motility?

(a) Gastrin

(b) Secretin

(c) Gastric Inhibitory Peptide (GIP)

(d) Cholecystokinin (CCK)

Explanation: GIP reduces gastric activity, aiding in digestion and nutrient absorption.

19. The pancreas acts as:

(a) An endocrine gland only

(b) An exocrine gland only

(c) Both endocrine and exocrine gland

(d) Neither endocrine nor exocrine

Explanation: The pancreas has dual functions, secreting insulin and glucagon as an endocrine gland and digestive enzymes as an exocrine gland.

20. Which of the following is a hyperglycemic hormone?

(a) Insulin

(b) Glucagon

(c) Thyroxine

(d) Progesterone

Explanation: Glucagon increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis.

21. The adrenal medulla secretes:

(a) Glucocorticoids

(b) Adrenaline and noradrenaline

(c) Aldosterone

(d) Testosterone

22. Which hormone promotes the development of female secondary sexual characteristics?

(a) Testosterone

(b) Estrogen

(c) Progesterone

(d) Oxytocin

23. The thymus gland is primarily responsible for:

(a) Stimulating digestion

(b) Regulating circadian rhythm

(c) Immune system development

(d) Water reabsorption

24. Diabetes insipidus is caused by a deficiency of:

(a) Insulin

(b) Vasopressin

(c) Thyroxine

(d) Glucagon

25. The target tissue of luteinizing hormone (LH) in females is:

(a) Mammary glands

(b) Ovarian follicles

(c) Hypothalamus

(d) Pineal gland

26. The hormone responsible for stimulating the production of red blood cells (RBCs) is:

(a) Vasopressin

(b) Erythropoietin

(c) Cortisol

(d) Adrenaline

27. Which hormone supports pregnancy and maintains the uterus lining?

(a) Estrogen

(b) Progesterone

(c) Oxytocin

(d) Prolactin

28. Which hormone regulates the sleep-wake cycle in humans?

(a) Vasopressin

(b) Thyroxine

(c) Melatonin

(d) Oxytocin

29. The hormone insulin is secreted by:

(a) Adrenal medulla

(b) Thyroid gland

(c) Beta cells of the pancreas

(d) Parathyroid gland

30. Which of the following hormones decreases blood calcium levels?

(a) Parathyroid hormone (PTH)

(b) Thyrocalcitonin (TCT)

(c) Glucagon

(d) Aldosterone

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