Lignin is the important constituent in the cell wall of

Options

A. cambium
B. parenchyma
C. phloem
D. xylem parenchyma

Answer

### Step-by-Step Solution:

1. **Identify the Components of Plant Cell Walls**:
- Plant cell walls are primarily composed of cellulose, hemicellulose, and lignin. Lignin is a complex organic polymer that provides rigidity and strength to the cell wall.

2. **Understand the Role of Vascular Tissues**:
- In plants, there are two main types of vascular tissues: xylem and phloem.
- Xylem is responsible for transporting water and minerals from the roots to the rest of the plant, while phloem transports the products of photosynthesis (food) throughout the plant.

3. **Focus on Xylem**:
- Xylem is a permanent tissue that consists of various cell types including vessels, tracheids, parenchyma, and fibers.
- The xylem fibers are dead cells that contain lignin, which is crucial for providing mechanical support to the plant.

4. **Examine Other Options**:
- **Phloem**: Contains sieve tubes and companion cells but does not primarily contain lignin.
- **Parenchyma**: Mainly involved in storage and photosynthesis, and does not have significant lignin content.
- **Cambium**: A layer of undifferentiated cells located between xylem and phloem, responsible for the growth of new cells, but does not contain lignin.

5. **Conclusion**:
- Based on the information, lignin is an important constituent of the cell wall in **xylem**.

### Final Answer:
Lignin is the important constituent in the cell wall of **xylem**.

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