Which of the following is correct regarding the excretion ?

Options

A. Large amount of water from renal filtrate is reabsorbed in DCT and a less amount is reabsorbed by PCT
B. The descending limb of loop of Henle is completely impermeable to NaCl salt.
C. Malpighian corpuscle is found in medulla region of kidney.
D. The colour of urine is pale yellow and is slightly alkaline in nature.

Answer

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

### Step 1: Analyze the first statement
**Statement:** Large amount of water from renal filtrate is reabsorbed in DCT (Distal Convoluted Tubule) and less amount is reabsorbed by PCT (Proximal Convoluted Tubule).

**Analysis:** This statement is incorrect. The majority of water reabsorption occurs in the Proximal Convoluted Tubule (PCT), not in the Distal Convoluted Tubule (DCT). The DCT primarily reabsorbs sodium ions and is less involved in water reabsorption compared to the PCT.

### Step 2: Analyze the second statement
**Statement:** The descending loop of Henle is completely impermeable to NaCl (salt).

**Analysis:** This statement is correct. The descending limb of the loop of Henle is indeed impermeable to NaCl, allowing water to be reabsorbed while NaCl remains in the tubular fluid.

### Step 3: Analyze the third statement
**Statement:** Malpighian corpuscle is found in the medulla region of the kidney.

**Analysis:** This statement is false. The Malpighian corpuscle, which consists of Bowman's capsule and the glomerulus, is located in the cortex region of the kidney, not the medulla.

### Step 4: Analyze the fourth statement
**Statement:** The color of urine is pale yellow and slightly alkaline in nature.

**Analysis:** This statement is also false. While urine can be pale yellow, its pH is typically slightly acidic, not alkaline. The color of urine can vary based on hydration and other factors.

### Conclusion
After analyzing all the statements, the correct statement regarding excretion is:
- The descending loop of Henle is completely impermeable to NaCl (salt).

### Final Answer
The correct option is: The descending loop of Henle is completely impermeable to NaCl (salt).

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