Companion cells are closely associated with
1 Vessel elements
2 Trichomes
3 Guard cells
4 Sieve elements

Options

A. Vessel elements
B. Trichomes
C. Guard cells
D. Sieve elements

Answer

**Step-by-Step Solution:**

1. **Understanding Companion Cells:**
Companion cells are specialized parenchyma cells found in the phloem tissue of flowering plants. Their primary function is to assist in the transport of nutrients and maintain the pressure gradient in sieve tubes.

2. **Identifying Associations:**
To determine with which structures companion cells are closely associated, we need to look at the options provided:
- **Vessel Elements:** These are part of the xylem and are not associated with companion cells.
- **Trichomes:** These are epidermal structures that help reduce water loss and are not related to companion cells.
- **Guard Cells:** These cells surround the stomata and regulate gas exchange, but they are not associated with companion cells.
- **Sieve Elements:** These are the primary components of the phloem that transport sugars and nutrients. Companion cells are closely associated with sieve elements.

3. **Conclusion:**
Based on the functions and associations of the structures mentioned, the correct answer is that companion cells are closely associated with **sieve elements**.

**Final Answer:**
4. **Sieve elements**

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