Meristematic tissue responsible for increase in girth of tree trunk is

Options

A. Apical meristem
B. Intercalary meristem
C. Lateral meristem
D. Phellogen

Answer

To solve the question regarding which meristematic tissue is responsible for the increase in the girth of a tree trunk, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Meristematic Tissues**:
- There are three main types of meristematic tissues:
- **Apical Meristem**: Located at the tips of roots and shoots, responsible for vertical growth (length).
- **Intercalary Meristem**: Found at the nodes and the base of leaves, responsible for the elongation of stems and leaves.
- **Lateral Meristem**: Located along the sides of stems and roots, responsible for increasing the girth (width) of the plant.

2. **Identify the Function of Each Meristem**:
- **Apical Meristem**: Increases the height of the plant.
- **Intercalary Meristem**: Contributes to the elongation of the plant.
- **Lateral Meristem**: Involved in secondary growth, which increases the girth of the plant.

3. **Focus on the Girth of the Tree Trunk**:
- The question specifically asks about the increase in girth. Therefore, we need to identify which meristematic tissue contributes to this aspect of growth.

4. **Conclusion**:
- The lateral meristem is responsible for the increase in girth of the tree trunk. This is also known as the cambium, which facilitates the formation of secondary xylem and phloem, leading to an increase in trunk diameter.

### Final Answer:
The meristematic tissue responsible for the increase in girth of the tree trunk is the **lateral meristem**.

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