| Assertion (A): | Urea is the primary nitrogenous waste in humans. |
| Reason (R): | It is less toxic and more soluble in water compared to ammonia. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A) |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
| 1. | PCT | 2. | Henle's loop |
| 3. | DCT | 4. | Collecting duct |
| I: | Ascending limb of loop of Henle |
| II: | Distal convoluted tubule |
| 1. | more concentrated than filtrate exiting the loop Henle. |
| 2. | less concentrated than filtrate exiting the loop of Henle. |
| 3. | more voluminous than filtrate exiting the loop of Henle. |
| 4. | less voluminous than filtrate exiting the loop of Henle. |
| Assertion (A): | Atrial Natriuretic Factor (ANF) mechanism acts as a check on the renin-angiotensin mechanism. |
| Reason (R): | An increase in blood flow to the atria of the heart can cause the release of ANF. |
| 1. | Both (A) and (R) are True and (R) correctly explains (A). |
| 2. | Both (A) and (R) are True but (R) does not correctly explain (A). |
| 3. | (A) is True; (R) is False. |
| 4. | Both (A) and (R) are False. |
| I: | Cartilaginous fishes are ammonotelic. |
| II: | Mammals are ureotelic. |
| III: | Land snails are uricotelic. |
| Statement I: | ADH increases water reabsorption in the collecting ducts of the nephron. |
| Statement II: | ADH secretion is stimulated when blood osmolarity decreases. |
| 1. | Statement I is correct; Statement II is correct. |
| 2. | Statement I is correct; Statement II is incorrect. |
| 3. | Statement I is incorrect; Statement II is correct. |
| 4. | Statement I is incorrect; Statement II is incorrect. |
| I: | They are located at the level of T12 – L2-L3 vertebrae |
| II: | Left kidney is slightly lower placed than the right kidney |
| Assertion (A): | The ascending limb of loop of Henle is also called the diluting segment of the nephron. |
| Reason (R): | In the ascending portion, the loop becomes impermeable to water and the cells of the loop actively reabsorb solutes from the luminal fluid. |
| 1. | (A) is True but (R) is False. |
| 2. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 3. | (A) is False but (R) is True. |
| 4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |