The cell wall of xylem cells is rich in

Options

A. Lipid
B. Protein
C. Lignin
D. Starch

Answer

### Step-by-Step Solution:

1. **Understanding Xylem Structure**: Xylem is a complex permanent tissue in plants responsible for the transport of water and minerals from the roots to the rest of the plant. It consists of various cell types, including xylem vessels, tracheids, and fibers.

2. **Composition of Xylem Cell Walls**: The cell walls of xylem cells are primarily composed of several components, including cellulose, hemicellulose, and lignin.

3. **Identifying the Key Component**: Among these components, lignin is particularly significant. It is a complex organic polymer that provides rigidity and strength to the cell walls.

4. **Role of Lignin**: The deposition of lignin in the secondary cell walls of xylem cells contributes to their structural support and protects them from microbial attack. This is essential for the durability and functionality of xylem tissue.

5. **Conclusion**: Therefore, the cell wall of xylem cells is rich in lignin, making it the correct answer to the question.

### Final Answer:
The cell wall of xylem cells is rich in **lignin**.

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