which tissue gives rise to secondary growth

Options

A. apical meristem
B. adventitious root
C. axillary bud
D. vascular cambium.

Answer

**Step-by-Step Solution:**

1. **Understanding Secondary Growth**: Secondary growth refers to the increase in thickness or girth of the plant, which occurs primarily in dicots and some gymnosperms. It is different from primary growth, which increases the length of the plant.

2. **Identifying the Tissues Involved**: The main tissues involved in secondary growth are the vascular cambium and cork cambium. The vascular cambium is particularly important as it produces secondary xylem (wood) and secondary phloem.

3. **Differentiating Between Meristems**:
- **Apical Meristem**: Responsible for primary growth (lengthening) at the tips of roots and shoots.
- **Adventitious Roots**: These are roots that arise from non-root tissues, not specifically involved in secondary growth.
- **Axillary Buds**: These are involved in the formation of branches and also do not contribute to secondary growth.

4. **Focusing on Vascular Cambium**: The vascular cambium is a type of lateral meristem that forms between the xylem and phloem. It is responsible for the production of secondary vascular tissues, which include:
- **Secondary Xylem**: Contributes to wood formation.
- **Secondary Phloem**: Involved in the transport of nutrients.

5. **Conclusion**: The tissue responsible for secondary growth is the vascular cambium. It is the only option among the given choices that contributes to the thickening of stems and roots in dicots.

**Final Answer**: The tissue that gives rise to secondary growth is the **vascular cambium**.

---