What are microvilli? State their functions.

Explanation

### Step-by-Step Solution

1. **Definition of Microvilli**:
Microvilli are tiny, finger-like projections found on the surface of epithelial cells, particularly in the intestinal mucosa. They extend from the surface of the cells lining the small intestine.

2. **Structure of Microvilli**:
Microvilli are composed of a core of actin filaments, which are part of the cytoskeleton of the cell. This structure allows them to maintain their shape and increase the surface area of the cell.

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