NEET Biology: Excretory System questions with solutions

Q1. Which one of the following statements in regard to the excretion by the human kidneys is correct?

1. Descending limb of loop of Henle is impermeable to water
2. Distal convoluted tubule is incapable of reabsorbing \( N a^{+} \) ions
3. Nearly 99 percent of the glomerular filtrate is reabsorbed by the rental tubules.
4. Ascending limb of loop of Henle is impermeable to electrolytes.

Answer: Nearly 99 percent of the glomerular filtrate is reabsorbed by the rental tubules.

The kidneys filter a large volume of fluid, but almost all of it is reabsorbed along the renal tubules, leaving only a small fraction to become urine. The other statements are incorrect because the descending limb is water-permeable, the distal tubule can reabsorb sodium, and the ascending limb is impermeable to water, not electrolytes.

Q2. The liquid which is collected in the cavity of Bowman's capsule is

1. concentrated urine
2. Blood plasma minus blood proteins and corpuscles
3. Glycogen and water
4. Sulphates and water

Answer: Blood plasma minus blood proteins and corpuscles

Bowman’s capsule collects the glomerular filtrate, which is essentially blood plasma after filtration. Blood cells and most plasma proteins are too large to pass through the filtration barrier, so they remain in the bloodstream.