Which one does not enter nephron

Options

A. Water
B. Glucose
C. Plasma proteins
D. Urea

Answer

To determine which substance does not enter the nephron, we can analyze the options provided: water, glucose, plasma proteins, and urea.

### Step-by-Step Solution:

1. **Understanding the Nephron Structure**:
- The nephron is the functional unit of the kidney, consisting of a glomerulus and a tubule. The glomerulus is responsible for filtering blood.

2. **Filtration Process**:
- During the filtration process, blood enters the glomerulus, where ultrafiltration occurs. This process allows certain substances to pass through the glomerular membrane into the nephron while preventing others from entering.

3. **Analyzing the Options**:
- **Water**: Water is a small molecule that can easily pass through the glomerular membrane and enters the nephron.
- **Glucose**: Glucose is also a small molecule and can pass through the glomerular membrane, entering the nephron.
- **Urea**: Urea is a waste product that is small enough to be filtered and enters the nephron as well.
- **Plasma Proteins**: Plasma proteins are large molecules that cannot pass through the glomerular membrane. They remain in the blood and do not enter the nephron.

4. **Conclusion**:
- Based on the analysis, the substance that does not enter the nephron is **plasma proteins**.

### Final Answer:
The correct answer is **plasma proteins**.

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