NCERT Exemplars: Chemical Coordination & Integration - 1 - Biology Class 11 - NEET

Multiple Choice Questions

Q.1. Select the right match of the endocrine gland and their hormone among the options given below:

Options:
(a) A-iv, B-ii, C-iii, D-i
(b) A-ii, B-iv, C-i, D-iii
(c) A-iv, B-ii, C-i, D-iii
(d) A-ii, B-iv, C-iii, D-i
Ans. (d)
Solution:

Q.2. Which of the following hormones is not secreted by anterior pituitary.
(a) Growth hormone
(b) Follicle-stimulating hormone
(c) Oxytocin
(d) Adrenocorticotropic hormone
Ans. (c)
Solution: The pars distalis region of pituitary, commonly called anterior pituitary, produces 6 Growth Hormone (GH), Prolactin (PRL), Thyroid Stimulating Hormone (TSH), Adrenocorticotropic hormone (ACTH), Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). Neurohypophysis (pars nervosa) also known as posterior pituitary, stores and releases two hormones called oxytocin and vasopressin, which are actually synthesised by the hypothalamus and are transported axonally to neurohypophysis.

Q.3. Mary is about to face an interview. But during the first five minutes before the interview she experiences sweating, increased rate of heartbeat, respiration, etc. Which hormone is responsible for her restlessness?
(a) Estrogen and Progesterone
(b) Oxytocin and Vasopressin
(c) Adrenaline and Noradrenaline
(d) Insulin and Glucagon
Ans. (c)
Solution: Mary is about to face an interview. But during the first five minutes before the interview she experiences sweating, increased rate of heartbeat, respiration, etc. Adrenaline and noradrenaline hormone are responsible for her restlessness.

Q.4. The steroid responsible for balance of water and electrolytes in our body is
(a) Insulin
(b) Melatonin
(c) Testosterone
(d) Aldosterone
Ans. (d)
Solution: Vasopressin acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduces loss of water through urine (diuresis). Hence, it is also called as anti-diuretic hormone (ADH).

Q.5. Thymosin is responsible for
(a) Raising the blood sugar level
(b) Raising the blood calcium level
(c) Differentiation of T lymphocytes 
(d) Decrease in blood RBC
Ans. (c)
Solution: Thymosin is a thymus-secreted enzyme. Thymosin is responsible for differentiation of T-lymphocytes. 

Thymosin also works to grow B cells into plasma cells in order to produce antibodies.

Q.6. In the mechanism of action of a protein hormone, one of the second messengers is
(a) Cyclic AMP
(b) Insulin
(c) T₃
(d) Gastrin
Ans. (a)
Solution: Hormones which interact with membrane-bound receptors normally do not enter the target cell, but generate secondary messengers (e.g., cyclic AMP, cGMP, DAG, IP₃, Ca⁺⁺ etc.) which in turn regulate cellular metabolism.

Q.7. Leydig cells produce a group of hormones called
(a) Androgens
(b) Estrogens
(c) Aldosterone
(d) Gonadotropins
Ans. (a)
Solution: The Leydig's cells present in the connective tissue between seminiferous tubules produce a group of hormones called androgens mainly testosterone.

Q.8. Corpus luteum secretes a
(a) Prolactin
(b) Progesterone
(c) Aldosterone
(d) Testosterone
Ans. (b)
Solution: In the luteal phase, corpus luteum is formed by the remaining tissue of the ruptured Graafian follicle after ovulation. Corpus luteum secretes a large amount of progesterone for the proliferation and maintenance of the endometrium for the implantation of the fertilized ovum.

Q.9. Cortisol is secreted from gland called
(a) Pancreas
(b) Thyroid
(c) Adrenal
(d) Thymus
Ans. (c)
Solution: Adrenal or suprarenal glands are paired structures located on the top of the kidneys. The cells of Zopa fasciculate of adrenal cortex secretes mainly glucocorticoids. Glucocorticoids include three main hormones: cortisol(= hydrocortisone), corticosterone and cortisone. They affect carbohydrate metabolism, however, they also affect the metabolism of proteins and fats.

Q.10. A hormone responsible for normal sleep-wake cycle is
(a) Epinephrine
(b) Gastrin
(c) Melatonin
(d) Insulin
Ans. (c)
Solution: A hormone responsible for normal sleep-wake cycle is melatonin.

Melatonin is a hormone secreted by pineal gland. Immediately above the optic chiasma(in the brain) in a nucleus, are present melatonin receptors that react to this hormone and synchronise the nucleus to the 24hrs day/night rhythm, thus informing the brain when it is day and when it is night.

Q.11. Hormones are called chemical signals that stimulate specific target tissues. Which is the correct location of these receptors in case of protein hormones?
(a) Extracellular matrix
(b) Blood
(c) Plasma membrane
(d) Nucleus
Ans. (c)
Solution: Hormones of protein nature binds to specific receptor molecules located on the plasma membrane to form the hormone-receptor complex.

Q.12. Choose the correct option among the following:

Options:
(a) A—(ii), B—(i), C—(iii), D—(iv)
(b) A—(iv), B—(i), C—(iii), D—(ii)
(c) A—(i), B—(ii), C—(iii), D—(iv)
(d) A—(i), B—(iv), C—(ii), D—(iii)
Ans. (b)
Solution: 

A. Role of epinephrine and non- epinephrine: They whip up metabolism for preparing the animal to face special conditions created by physical stress such as fall in BP or blood sugar, anger, fear etc. All these conditions require more energy which is provided by increasing heart rate, blood pressure, sugar level of blood.

B. Testosterone: It stimulates the development of male accessory sex characters such as hair on the face, growth and distribution of hair on the body, stronger bones and muscles.

C. Glucagon: It is secreted by alpha cells of the islands of Langerhans in response to a fall in the blood glucose level. It brings about change of liver glycogen to blood glucose( glycogenolysis).

D. Atrial natriuretic factor: The cells, called cardiocytes, of the atria, secrete a peptide, ANF in response to an increased return of the venous blood. This hormone regulates the blood volume through increased excretion of ions and water.

Q.13. Which of the following do not play any role in calcium balance in the human body?
(a) Vitamin D
(b) Parathyroid hormone
(c) Thyrocalcitonin
(d) Thymosin
Ans. (d)
Solution: Thymosin is a hormone released by the thymus. It has a major role in the maturation of the T lymphocytes. It has no role in maintaining the calcium balance in the body.

Q.14. Which of the following organs in mammals does not consist of a central medullary region surrounded by a cortical region?
(a) Ovary
(b) Adrenal
(c) Liver
(d) Kidney
Ans. (c)

1. The ovaries are solid organs and are composed of connective tissue, the stroma. The stroma consists of an outer ovarian cortex and central ovarian medulla.
2. Adrenal: The adrenals are conical, yellowish bodies. Each has two distinct regions are called adrenal cortex and adrenal medulla.
3. Kidney:  The two regions of the kidney are outer region is called renal cortex and inner region is termed renal medulla.

So, the correct answer is 'Liver'.

Q.15. Which of the following conditions is not linked to deficiency of thyroid hormones?
(a) Cretinism
(b) Goitre
(c) Myxedema
(d) Exophthalmia
Ans. (d)
Solution: 

• Exophthalmos happen due to hyperthyroidism. 
• Hypothyroidism is a disorder caused due to deficiency of thyroid hormone. It may lead to cretinism, myxoedema, simple goitre, Hashimoto's disease. 
• Exophthalmic goitre is thyroid enlargement in which thyroid secretes excessive amount of thyroid hormone. It is caused due to hypersecretion of thyroid hormone.

Very Short Answer Type Questions

Q.1. There are many endocrine glands in human body. Name the glands which is absent in male and the one absent in female.
Ans. Ovary is absent in male and testis is absent in female.

Q.2. Which of the two adrenocortical layers, zona glomerulosa and zona reticularis lies outside enveloping the other?
Ans. Zona glomerulosa is the outermost layer and zona reticularis is the innermost layer of adrenal gland.

Q.3. What is erythropoiesis? Which hormone stimulates it?
Ans. Formation of RBCs from the bone marrow is called erythropoiesis. It is stimulated by the hormone erythropoietin.

Q.4. Name the only hormone secreted by pars intermedia of the pituitary gland.
Ans. Melanocyte Stimulating Hormone (MSH)

Q.5. Name the endocrine gland that produces calcitonin and mention the role played by this hormone.
Ans. Calcitonin or thyrocalcitonin is secreted by thyroid gland. Calcitonin regulates blood calcium level.

Q.6. Name the hormone that helps in cell-mediated immunity.
Ans. Thymosin

Q.7. What is the role of second messenger in the mechanism of protein hormone action?
Ans. Second messenger regulates cell metabolism. Hormones which interact with membrane-bound receptors normally do not enter the cell. Instead, they generate second messengers and thus affect the functioning of the target cells.

Q.8. State whether true or false:
(a) Gastrointestinal tract, kidney and heart also produce hormones.
Ans. True
(b) Pars distalis produces six trophic hormones.
Ans. True
(c) B-lymphocytes provide cell-mediated immunity.
Ans. False
(d) Insulin resistance results in a disease called diabetes mellitus.
Ans. True

Q.9. A patient complains of constant thirst, excessive passing of urine and low blood pressure. When the doctor checked the patient's blood glucose and blood insulin level, the level were normal or slightly low. The doctor diagnosed the condition as diabetes insipidus. But he decided to measure one more hormone in patients blood. Which hormone does the doctor intend to measure?
Ans. Vasopressin or Anti-Diuretic Hormone because low level of this hormone can result in excessive passing of urine and low blood pressure.

Q.10. Correct the following statements by replacing the term underlined.
(a) Insulin is a steroid hormone.
Ans. (a) Insulin is a peptide hormone.
(b) TSH is secreted from the corpus luteum.
Ans. TSH is secreted from anterior pituitary gland.
(c) Tetraiodothyronine is an emergency hormone.
Ans. Tetraiodothyronine is a maintenance hormone.
(d) The pineal gland is located on the anterior part of the kidney.
Ans. The adrenal gland is located on the anterior part of the kidney.

Q.11. Rearrange the following hormones in Column I so as to match with their chemical nature in Column II.

Ans. (a) → (iii), (b) → (i), (c) → (ii), (d) → (iv)