This set of Class 11 Biology Chapter 19 Multiple Choice Questions & Answers (MCQs) focuses on “Regulation of Excretory System”.
1. Which of these are not involved in the regulation of kidney function?
Explanation: The functions of the kidneys are regulated by several organs of the body, such as the hypothalamus, the heart and the JGA or the juxtaglomerular apparatus, and some of their hormones.
2. Which of these do not activate osmoreceptors?
a) Blood volume
b) Body fluid volume
d) Ionic concentration
Explanation: Osmoreceptors are activated by the blood volume, the body fluid volume and the ionic concentration. When these elements are within the normal range, or during homeostasis, the osmoreceptors are not active.
3. What is another name for ADH?
Explanation: Another name for ADH or the antidiuretic hormone is vasopressin. It is released from the pituitary gland. The functions of ADH or vasopressin include prevention of diuresis and increasing blood pressure.
4. Where is vasopressin released from?
b) Pineal gland
c) Adrenal gland
Explanation: Vasopressin or the antidiuretic hormone (ADH) is released from the neurohypophysis or the posterior lobe of the pituitary gland. Oxytocin is also released from here. ADH prevents diuresis.
5. Which of these is not a function of ADH?
a) Stimulates water reabsorption
b) Decreases blood pressure
c) Prevents diuresis
d) Decreases perspiration
Explanation: ADH or the antidiuretic hormone is also known as vasopressin. Vasopressin stimulates water reabsorption from the kidneys, prevents diuresis, decreases perspiration and increases blood pressure.
6. Which of these hormones do not lead to the constriction of blood vessels?
b) Angiotensin II
Explanation: Epinephrine, which is released from the adrenal medulla, ADH or vasopressin, which is released from the posterior pituitary gland and angiotensin II lead to the constriction of blood vessels. They are vasoconstrictors.
7. Which of the following can increase GFR?
a) Increase in blood pressure
b) Decrease in blood pressure
c) Increased Bowman’s capsule hydrostatic pressure
d) Ureteral constriction
Explanation: GFR or the glomerular filtration rate of the kidneys can be increased by increasing the blood pressure. The higher the pressure with which blood flows through the glomerulus, the higher is the rate of filtration.
8. On which of these does ADH act upon?
b) Loop of Henle
d) Collecting duct
Explanation: ADH or the antidiuretic hormone acts upon the latter parts of the nephron to increase reabsorption and prevent diuresis. Hence, ADH or vasopressin mainly acts upon the DCT and the collecting duct.
9. A fall in GFR can stimulate the juxtaglomerular cells to release which hormone from the kidney?
d) Angiotensin I
Explanation: A fall in the GFR or the glomerular filtration rate leads to the release of renin from the kidney. Renin converts the inactive angiotensinogen present in blood to its active form, angiotensin I.
10. Aldosterone decreases the reabsorption of sodium ions. True or false?
Explanation: Aldosterone is a hormone which is released from the adrenal cortex. It increases the reabsorption of sodium ions and water from the latter parts of the nephrons, such as the DCT and the collecting tube.
11. Which of these hormones converts angiotensinogen to angiotensin I?
c) Angiotensin II
Explanation: Renin is a hormone released by the juxtaglomerular cells of the kidney when there is a fall in the glomerular filtration rate (GFR). It converts the inactive angiotensinogen present in blood to angiotensin I.
12. Which of these hormones activates the adrenal cortex to release aldosterone?
c) Angiotensin II
d) Angiotensin I
Explanation: When the GFR decreases, the juxtaglomerular cells of the kidney release renin, which converts angiotensinogen to angiotensin I and further to angiotensin II. Angiotensin II activates the adrenal cortex to release aldosterone.
13. Which of these hormones can decrease blood pressure?
d) Angiotensin II
Explanation: Angiotensin II, epinephrine and ADH or the antidiuretic hormone or vasopressin are vasoconstrictors. They can increase blood pressure. ANF or the Atrial Natriuretic Factor is a vasodilator and can decrease blood pressure.
14. Which of these hormones acts as a check on the renin-angiotensin mechanism?
Explanation: ANF or the Atrial Natriuretic Factor is a vasodilator and can decrease blood pressure. It acts as a check on the renin-angiotensin mechanism that is activated when the glomerular filtration rate decreases.
15. Where is aldosterone released from?
a) Pituitary gland
b) Adrenal cortex
c) Pineal gland
d) Adrenal medulla
Explanation: Aldosterone is released from the zona glomerulosa of the adrenal cortex. It is a mineralocorticoid hormone that increases the reabsorption of sodium ions and water from the distal parts of the nephron.
Sanfoundry Global Education & Learning Series – Biology – Class 11.
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