Which of the following fibres are made of proteins ?

Options

A. silk and cotton
B. natural silk and artificial silk
C. rayon and wool
D. wool and silk

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which fibers are made of proteins. We need to identify the fibers listed in the options and determine their composition.

2. **Analyzing the Options**:
- **Option 1: Silk and Cotton**:
- Silk is a natural fiber made from the protein fibroin produced by silkworms.
- Cotton, on the other hand, is made of cellulose, which is a carbohydrate, not a protein.
- **Conclusion**: Only silk is made of proteins in this option.

3. **Option 2: Natural Silk and Artificial Silk**:
- Natural silk, as mentioned, is made of proteins.
- Artificial silk (like rayon) is a synthetic fiber and does not contain proteins; it is made from regenerated cellulose.
- **Conclusion**: Only natural silk is made of proteins in this option.

4. **Option 3: Rayon and Wool**:
- Wool is a natural fiber made from the protein keratin, which is found in sheep's fleece.
- Rayon is a man-made fiber derived from cellulose and does not contain proteins.
- **Conclusion**: Only wool is made of proteins in this option.

5. **Option 4: Wool and Silk**:
- Both wool and silk are natural fibers.
- Wool is made from the protein keratin, and silk is made from the protein fibroin.
- **Conclusion**: Both fibers in this option are made of proteins.

6. **Final Answer**: The correct answer is **Option 4: Wool and Silk**.

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