Which is living mechanical tissue?

Options

A. phloem
B. parenchyma
C. collenchyma
D. sclerenchyma

Answer

### Step-by-Step Solution:

1. **Understanding Mechanical Tissues**:
- Mechanical tissues in plants provide structural support and strength. They help the plant maintain its shape and resist various forces.

2. **Identifying the Options**:
- The question asks for a living mechanical tissue. The common types of mechanical tissues include collenchyma, sclerenchyma, and parenchyma, among others.

3. **Evaluating Phloem**:
- Phloem is primarily responsible for the transport of nutrients and does not provide mechanical support. Therefore, phloem cannot be considered a living mechanical tissue.

4. **Evaluating Parenchyma**:
- Parenchyma cells are living cells that mainly function in storage and transport of substances. They do not provide mechanical support, making them an incorrect choice for living mechanical tissue.

5. **Evaluating Collenchyma**:
- Collenchyma is a type of living mechanical tissue. It consists of elongated cells with irregularly thickened walls, which provide flexibility and support to young plant parts, allowing them to grow and bend without breaking.

6. **Evaluating Sclerenchyma**:
- Sclerenchyma provides mechanical support as well but is composed of dead cells. Since the question specifies living mechanical tissue, sclerenchyma is not the correct answer.

7. **Conclusion**:
- The correct answer is collenchyma, as it is a living mechanical tissue that provides support and flexibility to the plant.

### Final Answer:
- **Collenchyma** is the living mechanical tissue.