NEET Biology Chemical Coordination and Integration MCQs Set 22

Answer: (b) prolactin

Explanation:
1. Prolactin (also called leuteotrophic) hormone is associated with lactation (secretion of milk from the mammary gland).
2. Therefore, to yield more milk cow is injected with prolactin hormone.
3. Hence option (b) is correct: prolactin

Teacher's Note:
1. Sorbitol is a sweetner found in some fruits (like apple, peers etc).
2. Gonadotrophs a type of basophil in the adenohypohysis (anterior pituitary gland) whose granules secrete FSH (follicele-stimulating hormone) and LH (luteinizing hormone).

Answer: (c) adrenaline

Explanation:
1. Adrenaline (amine hormone) is secreted by adrenal medulla on stimulation of sympathetic nervous system for meeting an emergency or stress condition like fear injury accident etc.
2. Hence, it also called as emergency hormone.
3. Hence option (c) is correct: adrenaline

Teacher's Note:
1. It increases blood pressure, respiration rate, sugar level in blood etc.
2. It prepares the body to face stress at the time of interview by increasing heart beat.

Answer: (a) Oxytocin Milk ejection hormone

Explanation:
1. Oxytocin is the hormone secreted by posterior pituitary that causes contraction of the smooth muscles of myometrium during child birth and ejection of milk from the mammary glands.
2. Glucagon is secreted by the D-cells of islets of langerhans of pancreas.
3. Hence option (a) is correct: Oxytocin Milk ejection hormone

Teacher's Note:
1. Its main fuction is to increase blood glucose level.
2. Adrenaline (epinephrine) is secreted by adrenal medulla.

Answer: (b) Thymus - Starts undergoing atrophy after puberty

Explanation:
1. The thymus is an organ located in the upper anterior portion of the chest cavity just behind the sternum.
2. The thymus continues to grow between birth and puberty and then begins to atrophy.
3. Hence option (b) is correct: Thymus - Starts undergoing atrophy after puberty

Teacher's Note:
1. Proportional to thymic Chemical Co-ordination and Integration size, thymic activity is most active before puberty.
2. Upon atrophy, the size and activity are dramatically reduced, and the organ is primarily replaced with fat.

Answer: (b) milligram per deci litre

Explanation:
1. Blood glucose level is commonly expressed as milligram per deci litre.
2. Hence option (b) is correct: milligram per deci litre

Teacher's Note:
1. Endocrine questions: learn each gland with its hormones, target organs and the effect of excess or deficiency.
2. Antagonistic pairs such as insulin and glucagon, or calcitonin and parathormone, are frequently asked.

Answer: (a) Thyroxine

Explanation:
1. The main secretion of thyroid gland is called thyroxine.
2. Thyroxine contains iodine.
3. Hence option (a) is correct: Thyroxine

Teacher's Note:
1. When thyroid gland becomes inactive, the lack of iodine causes goitre.
2. Antagonistic pairs such as insulin and glucagon, or calcitonin and parathormone, are frequently asked.

Answer: (d) Parathyroid

Explanation:
1. Parathyroid gland secretes parathormone hormone, which regulates Ca++ and 2 4 PO  ion in body.
2. This gland works independently to pituitary gland.
3. Hence option (d) is correct: Parathyroid

Teacher's Note:
1. Endocrine questions: learn each gland with its hormones, target organs and the effect of excess or deficiency.
2. Antagonistic pairs such as insulin and glucagon, or calcitonin and parathormone, are frequently asked.

Answer: (b) Insulin and glucagon

Explanation:
1. Insulin lowers blood sugar levels.
2. While Glucagon raises blood sugar levels.
3. Hence option (b) is correct: Insulin and glucagon

Teacher's Note:
1. Antagonistic pairs such as insulin and glucagon, or calcitonin and parathormone, are frequently asked.
2. Endocrine questions: learn each gland with its hormones, target organs and the effect of excess or deficiency.

Answer: (b) Thymus

Explanation:
1. Thymus stimulates T-cells which regulate the production of antibodies.
2. Hence option (b) is correct: Thymus

Teacher's Note:
1. Antagonistic pairs such as insulin and glucagon, or calcitonin and parathormone, are frequently asked.
2. Endocrine questions: learn each gland with its hormones, target organs and the effect of excess or deficiency.

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

Explanation:
1. Adrenaline is an emergency hormone whose concentration increases under stress conditions. e.g. cold, stress.
2. Adrenaline is secreted from adrenal medulla.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. It initiates many bodily responses, including the stimulation of heart action and an increase in blood pressure, metabolic rate, and blood glucose concentration.
2. Antagonistic pairs such as insulin and glucagon, or calcitonin and parathormone, are frequently asked.

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

Explanation:
1. Based on the mode of secretion, the glands are of three types : mesocrine, apocrine and holocrine.
2. Mammary glands that are present in mammals to feed the young ones with milk are the example of apocrine glands.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. In apocrine glands, the secretion accumulates as secretory granules in the distal part of the cell.
2. This part later breaks down and leaves as a secretion.

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

Explanation:
1. Calcitonin or thyrocalcitonin is secreted by parafollicular cells of thyroid stroma.
2. It retards bone dissolution and stimulates excretion of calcium in urine.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Thus, it lowers calcium level in extra cellular fluid (ECF).
2. Parathormone is secreted by chief cells of parathyroid gland and is also known as Collip's hormone.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Vasopressin or antidiuretic hormone is secreted by posterior pituitary gland.
2. The deficiency of vassopressin results in a disorder known as diabetes insipidus.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. The main symptoms of diabetes insipidus are increase in thirst and increase in urination.
2. Endocrine questions: learn each gland with its hormones, target organs and the effect of excess or deficiency.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. Vasopressin or anti-diuretic hormone (ADH) reduces the volume of urine by increasing the reabsorption of water from the urine in the distal convoluted tubules, collecting tubules and collecting ducts in the kidney.
2. It does so by rendering the walls of these tubules leads to diabetes insipidus (increased urination).
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. Although the volume of urine is increased.
2. No glucose appears in the urine of such patients.