Identify the meristems that cause increase in girth are

Options

A. apical meristems and vascular cambium.
B. intercalary meristems and cork cambium.
C. vascular cambium and apical meristems.
D. cork cambium and vascular cambium

Answer

### Step-by-Step Solution:

1. **Understanding Meristems**:
- Meristems are regions in plants where cells can divide and contribute to growth. They are classified into two main types: primary and secondary meristems.

2. **Types of Growth**:
- Primary growth refers to the increase in length of the plant, which occurs at the apical (tip) and intercalary (between nodes) meristems.
- Secondary growth refers to the increase in girth (circumference) of the plant, which occurs in lateral meristems.

3. **Identifying Primary Meristems**:
- Apical meristems are located at the tips of roots and shoots, promoting vertical growth.
- Intercalary meristems are found at the base of leaves or internodes, contributing to elongation.

4. **Identifying Secondary Meristems**:
- The two main types of secondary meristems that contribute to an increase in girth are:
- **Vascular Cambium**: This layer of meristematic tissue is responsible for producing new vascular tissue (xylem and phloem), contributing to the thickness of the plant.
- **Cork Cambium**: This meristem produces cork cells that form the outer protective layer of the plant, also contributing to the increase in girth.

5. **Conclusion**:
- The meristems that cause an increase in girth are the **vascular cambium** and **cork cambium**.

### Final Answer:
The meristems that cause an increase in girth are **vascular cambium** and **cork cambium**.

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