Which of the following is true?

Options

A. Vessels are unicellular and with narrow lumen
B. Vessels are multicellular and with wide lumen
C. Trachieds are unicellular and with wide lumen
D. Tracheids and multicellular and with narrow lumen

Answer

To determine which statement is true regarding vessels and tracheids, we can analyze each option step by step:

### Step 1: Understanding Vessels
- **Definition**: Vessels are a type of xylem tissue found in vascular plants.
- **Structure**: Vessels are multicellular structures with a wide lumen.
- **Function**: They are primarily involved in the conduction of water and minerals and also provide mechanical support due to their thickened walls.
- **Perforation**: Vessels have perforated walls, allowing for efficient water transport.

### Step 2: Understanding Tracheids
- **Definition**: Tracheids are another type of xylem tissue, also found in vascular plants.
- **Structure**: Tracheids are unicellular and have a narrow lumen.
- **Function**: They also conduct water and minerals but are not perforated like vessels.
- **Cell Type**: Tracheids are unicellular, meaning they consist of a single cell.

### Step 3: Analyzing the Statements
- **Statement A**: "Vessels are unicellular with narrow lumen."
- This is incorrect because vessels are multicellular and have a wide lumen.

- **Statement B**: "Vessels are multicellular with wider lumen."
- This is correct as vessels are indeed multicellular and have a wide lumen.

- **Statement C**: "Tracheids are unicellular with wide lumen."
- This is incorrect because tracheids are unicellular but have a narrow lumen.

- **Statement D**: "Tracheids are multicellular with narrow lumen."
- This is incorrect because tracheids are unicellular, not multicellular.

### Conclusion
The only true statement among the options provided is **Statement B**: "Vessels are multicellular with wider lumen."