Which plants generally lack vessels in their xylem ?

Options

A. Monocots
B. Dicots
C. Gymnosperms
D. Angiosperms

Answer

To answer the question "Which plants generally lack vessels in their xylem?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Xylem Structure**:
- Xylem is a type of tissue in vascular plants responsible for the transport of water and minerals from the roots to the rest of the plant.
- It consists of various cell types, including tracheids and vessels.

2. **Identifying Vessel Presence**:
- Vessels are specialized structures found in the xylem of some plants, particularly angiosperms (flowering plants).
- Vessels facilitate efficient water transport due to their larger diameter compared to tracheids.

3. **Comparing Plant Groups**:
- **Angiosperms**: These plants have vessels in their xylem, which aids in efficient water transport.
- **Gymnosperms**: These plants do not have vessels; instead, they primarily contain tracheids for water conduction.
- **Monocots and Dicots**: Both of these groups are types of angiosperms and therefore possess vessels in their xylem.

4. **Conclusion**:
- Since gymnosperms are characterized by the absence of vessels in their xylem, the correct answer to the question is **gymnosperms**.

### Final Answer:
The plants that generally lack vessels in their xylem are **gymnosperms**.

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