which of the following statement is correct about excretion ?

Options

A. Human excretes 25-30gm urea per day
B. Glucose and amino acids are absorbed passively in renal tubules
C. Descending loop of Henle is impermeable to water
D. Kidneys reabsorbed `2//3 ^(rd)` part of glomerular filtrate.

Answer

To determine which statement is correct about excretion, let's analyze each option step by step:

1. **Understanding Excretion**: Excretion is the physiological process through which nitrogenous wastes are removed from the body. In humans, the primary nitrogenous waste is urea.

2. **Analyzing the Statements**:
- **Option 1**: "Humans excrete 25 to 30 grams of urea per day."
- This statement is correct. The average human does excrete approximately 25 to 30 grams of urea daily as a result of protein metabolism.

- **Option 2**: "Glucose and amino acids are absorbed passively in the renal tubule."
- This statement is incorrect. Glucose and amino acids are reabsorbed actively in the proximal convoluted tubule, not passively.

- **Option 3**: "Descending loop of Henle is impermeable to water."
- This statement is incorrect. The descending loop of Henle is actually permeable to water, allowing for water reabsorption.

- **Option 4**: "Kidney reabsorbs two-thirds part of the glomerular filtrate."
- This statement is also incorrect. The kidneys reabsorb about 99% of the glomerular filtrate, not just two-thirds.

3. **Conclusion**: After analyzing all the options, the correct statement regarding excretion is **Option 1**: "Humans excrete 25 to 30 grams of urea per day."