The vascular tissue in which annual rings vessels and fibers are present should be a

Options

A. Protoxylem
B. Metaxylem
C. Primary xylem
D. Secondary xylem

Answer

To solve the question regarding the vascular tissue in which annual rings, vessels, and fibers are present, we will analyze each option systematically.

### Step-by-Step Solution:

1. **Understanding Vascular Tissues**:
- Vascular tissues in plants are primarily composed of xylem and phloem. Xylem is responsible for water and nutrient transport, while phloem transports food.

2. **Identifying the Options**:
- The options provided are proto xylem, meta xylem, primary xylem, and secondary xylem.

3. **Analyzing Proto Xylem**:
- Proto xylem is the first form of xylem that develops from the procambium. It is not responsible for forming annual rings or fibers, as it primarily consists of smaller vessels and tracheids.
- **Conclusion**: Proto xylem is incorrect.

4. **Analyzing Meta Xylem**:
- Meta xylem is part of the primary xylem that differentiates after proto xylem. It has broader vessels and tracheids but does not form annual rings or significant fibers.
- **Conclusion**: Meta xylem is also incorrect.

5. **Analyzing Primary Xylem**:
- Primary xylem is formed during the primary growth of the plant and consists of proto xylem and meta xylem. It does not form annual rings as it is associated with the initial growth phase.
- **Conclusion**: Primary xylem is incorrect.

6. **Analyzing Secondary Xylem**:
- Secondary xylem is formed by the vascular cambium during secondary growth. It is responsible for the formation of annual rings and contains vessels, fibers, and tracheids. The fibers present in secondary xylem are known as wood fibers, which provide mechanical strength.
- **Conclusion**: Secondary xylem is the correct answer.

### Final Answer:
The vascular tissue in which annual rings, vessels, and fibers are present should be **secondary xylem**.

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