List the functions of a vacuole.

Explanation

### Step-by-Step Solution:

1. **Definition of Vacuole**:
- Vacuoles are membrane-bound sacs found within the cytoplasm of cells. They are surrounded by a membrane known as the tonoplast in plant cells.

2. **Presence in Different Organisms**:
- Vacuoles are present in various types of cells including plant, fungal, protist, animal, and bacterial cells. However, they are particularly prominent in plant cells.

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