Answer the following :
What are the constituents of phloem tissue?

Explanation

**Step-by-Step Solution:**

1. **Understanding Phloem Tissue**: Phloem is a type of vascular tissue in plants responsible for the transport of nutrients, particularly the products of photosynthesis (like sugars) from the leaves to other parts of the plant.

2. **Identifying the Constituents**: The phloem tissue is primarily composed of four main types of cells:
- **Sieve Tubes**: These are the main conduits for transporting sugars and other organic nutrients. They lack nuclei and rely on companion cells for their metabolic functions.
- **Companion Cells**: These cells are closely associated with sieve tubes and help in the maintenance and functioning of the sieve tubes. They contain a nucleus and are involved in the loading and unloading of sugars into the sieve tubes.
- **Phloem Parenchyma**: This type of cell serves as storage tissue and aids in the transport of nutrients. They are living cells that can store starch and other substances.
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