The primary growth in Equisetum stem occurs due to the activity of

Options

A. Apical meristem
B. Intercalary meristem
C. Lateral meristem
D. Primordial metistm

Answer

To answer the question "The primary growth in Equisetum stem occurs due to the activity of," we need to analyze the types of meristems and their roles in plant growth.

### Step-by-Step Solution:

1. **Understanding Primary Growth**:
- Primary growth refers to the increase in length of the plant. It occurs at the tips of roots and shoots.

2. **Identifying Types of Meristems**:
- **Apical Meristem**: Located at the tips of roots and shoots, responsible for the elongation of these parts.
- **Intercalary Meristem**: Found at the base of leaves or internodes, contributing to the growth in height.
- **Lateral Meristem**: Responsible for secondary growth, which increases the thickness or girth of the plant.
- **Primordial Meristem**: Composed of cells that can differentiate into various types of tissues but is not specifically responsible for primary growth.

3. **Focusing on Equisetum**:
- Equisetum, commonly known as horsetail, is a vascular plant that primarily exhibits primary growth through the activity of specific meristems.

4. **Determining the Correct Meristem**:
- In Equisetum, the primary growth is primarily due to the activity of the **apical meristem**. This meristem is crucial for the elongation of the stem and the formation of new leaves.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the primary growth in Equisetum stem occurs due to the activity of the **apical meristem**.

### Final Answer:
The primary growth in Equisetum stem occurs due to the activity of the **apical meristem**.

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