What are the constituents of phloem?

Explanation

**Step-by-Step Solution:**

1. **Understanding Phloem**: Phloem is a type of complex permanent tissue in plants. It plays a crucial role in the transportation of food (mainly sugars) throughout the plant.

2. **Constituents of Phloem**: Phloem is made up of four main components:
- **Sieve Tubes**: These are the primary conduits for transporting food. They are elongated cells that are connected end to end, forming long tubes.
- **Companion Cells**: These cells are closely associated with sieve tubes and help in the functioning of sieve tubes by providing them with metabolic support.
- **Phloem Parenchyma**: This is a type of ground tissue that is involved in storage and also helps in the transport of nutrients.
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