Read the following statements (a)in tubular reabsorption, substances like glucose, amino acid,Na^+, nitrogenous waste etc are reabsorbed by active transport, while reabsorption of water occur by passive transport (b) 50 -60% of electrolytes and water are absorbed by brush bordered cuboidal epithelium of PCT(c) conditional reabsorption of Na^+ and selective secretion of H^+ and K^+ occurs in DCT(d) filtrate gets concentrated as it moves upward in ascending limb of loop of henle. find the correct option regarding true or false statement.

Options

A. a(T),b(T),c(F),d(F)
B. a(F),b(T),c(F),d(F)
C. a(F),b(F),c(T),d(F)
D. a(T),b(F),c(T),d(f)

Answer

To solve the question regarding the statements about tubular reabsorption, we will analyze each statement one by one to determine whether they are true or false.

### Step-by-Step Solution:

1. **Statement (a)**: "In tubular reabsorption, substances like glucose, amino acid, Na^+, nitrogenous waste etc. are reabsorbed by active transport, while reabsorption of water occurs by passive transport."
- **Analysis**:
- Glucose, amino acids, and Na^+ are indeed reabsorbed by active transport.
- However, nitrogenous wastes are not primarily reabsorbed by active transport; they are often reabsorbed passively.
- Water reabsorption occurs passively through osmosis.
- **Conclusion**: This statement is **False**.

2. **Statement (b)**: "50-60% of electrolytes and water are absorbed by brush bordered cuboidal epithelium of PCT."
- **Analysis**:
- The proximal convoluted tubule (PCT) is lined with brush border cuboidal epithelium, which increases the surface area for reabsorption.
- In reality, about 70-80% of electrolytes and water are reabsorbed in the PCT, not just 50-60%.
- **Conclusion**: This statement is **False**.

3. **Statement (c)**: "Conditional reabsorption of Na^+ and selective secretion of H^+ and K^+ occurs in DCT."
- **Analysis**:
- The distal convoluted tubule (DCT) does indeed have conditional reabsorption of Na^+ and selective secretion of H^+ and K^+.
- This process helps maintain acid-base balance and electrolyte levels.
- **Conclusion**: This statement is **True**.

4. **Statement (d)**: "Filtrate gets concentrated as it moves upward in ascending limb of loop of Henle."
- **Analysis**:
- The ascending limb of the loop of Henle is impermeable to water and allows for the reabsorption of electrolytes.
- As electrolytes are reabsorbed, the filtrate actually becomes diluted, not concentrated.
- **Conclusion**: This statement is **False**.

### Summary of Statements:
- Statement (a): **False**
- Statement (b): **False**
- Statement (c): **True**
- Statement (d): **False**

### Final Answer:
The correct option regarding the true or false statements is that **statements (a), (b), and (d) are false, while statement (c) is true**.