Materials that are not filtered in Bowman's capsule are

Options

A. simple sugars
B. water
C. amino acids
D. proteins

Answer

### Step-by-Step Solution:

1. **Understanding the Bowman's Capsule**: The Bowman's capsule is a crucial structure in the nephron of the kidney, responsible for the initial filtration of blood. It collects the filtrate that will eventually form urine.

2. **Function of the Bowman's Capsule**: The primary function of the Bowman's capsule is to filter blood, removing waste products, excess substances, and water. This process is essential for maintaining homeostasis in the body.

3. **Components Filtered by the Bowman's Capsule**: The Bowman's capsule can filter small molecules such as water, glucose, amino acids, and ions. These substances are small enough to pass through the filtration membrane.

4. **Materials Not Filtered**: However, certain materials cannot be filtered due to their size. The two main components that are not filtered by the Bowman's capsule are:
- **Red Blood Cells (RBCs)**: These cells are too large to pass through the filtration membrane.
- **Proteins**: Proteins are also too large to be filtered through the Bowman's capsule.

5. **Conclusion**: Therefore, the materials that are not filtered in the Bowman's capsule include RBCs and proteins. Among the options provided, proteins are the most commonly recognized as not being filtered.

### Final Answer:
The materials that are not filtered in Bowman's capsule are **proteins**.

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