Describe structure of a vessel.

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Vessels**: Vessels are specialized components of the xylem tissue in flowering plants (angiosperms). They play a crucial role in the transport of water and minerals.

2. **Shape and Structure**: Vessels are long, cylindrical structures that have a tube-like appearance. This shape facilitates the efficient movement of water and nutrients.

3. **Cell Wall Composition**: The walls of the vessels are lignified, meaning they contain lignin, a complex organic polymer that provides rigidity and strength. This lignification is important for maintaining the structural integrity of the vessels under pressure.

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