The main mechanical tissue of plant is :

Options

A. Parenchyma
B. Collenchyma
C. Sclerenchyma
D. Both 2 and 3

Answer

To determine the main mechanical tissue of plants, we need to analyze the options provided: parenchyma, collenchyma, sclerenchyma, and both 2 and 3.

### Step-by-Step Solution:

1. **Understanding Mechanical Tissue**:
- Mechanical tissues in plants provide support and strength to various parts of the plant. They are essential for maintaining the structure and integrity of the plant.

2. **Evaluating Parenchyma**:
- Parenchyma is primarily involved in storage, photosynthesis, and tissue repair. It does not provide significant mechanical support. Thus, it is not considered a mechanical tissue.

3. **Evaluating Collenchyma**:
- Collenchyma is a living tissue that provides support, particularly in young and growing parts of the plant. Its cell walls are thickened at the corners, which helps in providing flexibility and mechanical strength to the plant.

4. **Evaluating Sclerenchyma**:
- Sclerenchyma is a type of mechanical tissue that consists of dead cells with thick lignified walls. It provides rigidity and strength to the plant, making it hard and stiff.

5. **Conclusion**:
- Since collenchyma (option 2) provides support to growing parts and sclerenchyma (option 3) provides rigidity and strength, both are considered mechanical tissues. Therefore, the correct answer is **both 2 and 3**.

### Final Answer:
The main mechanical tissue of plants is **both collenchyma and sclerenchyma**.

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