Brush border is characteristic of

Options

A. Neck of nephron
B. collecting tubule
C. Proximal convoluted tubule
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the characteristic feature known as "brush border" and which part of the nephron it is associated with.

2. **Identifying the Options**: The options provided are:
- Neck of nephron
- Collecting tubule
- Proximal convoluted tubule (PCT)
- All of the above

3. **Analyzing Each Option**:
- **Neck of Nephron**: This part does not have a brush border. It primarily functions in the passage of filtrate but lacks the specialized structures that increase surface area.
- **Collecting Tubule**: This section is responsible for collecting urine but does not have brush borders. Its main function is to concentrate urine by reabsorbing water and salts.
- **Proximal Convoluted Tubule (PCT)**: This part of the nephron is lined with simple cuboidal epithelial cells that have microvilli on their surface, forming what is known as the brush border. The brush border increases the surface area for reabsorption of water and nutrients.

4. **Conclusion**: Based on the analysis, the only part of the nephron that has a brush border is the Proximal Convoluted Tubule (PCT). Therefore, the correct answer is **Proximal Convoluted Tubule (PCT)**.

**Final Answer**: Brush border is characteristic of the Proximal Convoluted Tubule (PCT).

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