Grafting is successful in dicots but not in monocots because the dicots have-

Options

A. Vascular bundles arranged in a ring
B. Cambium for secondary growth
C. Vessels with elements arranged end to end
D. Cork cambium.

Answer

### Step-by-Step Solution:

1. **Understanding Grafting**: Grafting is a horticultural technique where tissues from one plant are inserted into those of another plant. The success of grafting depends on the compatibility of the tissues involved.

2. **Distinguishing Between Dicots and Monocots**:
- **Dicots**: These plants have two cotyledons and typically possess a vascular system arranged in a ring. They also have cambium tissue, which is crucial for secondary growth.
- **Monocots**: These plants have one cotyledon and their vascular bundles are scattered throughout the stem. They generally lack cambium tissue.

3. **Role of Cambium in Grafting**:
- Cambium is a type of meristematic tissue that can divide and differentiate into various types of cells. It is responsible for secondary growth, allowing plants to increase in thickness.
- In grafting, the cambium of the scion (the part being grafted) and the rootstock (the part receiving the graft) must align for successful tissue regeneration and growth.

4. **Why Grafting is Successful in Dicots**:
- The presence of cambium in dicots allows for the formation of new vascular tissues at the graft site, facilitating the integration of the two plant parts.
- The cambium's regenerative capacity is essential for the successful healing and growth of the grafted tissues.

5. **Why Grafting is Not Successful in Monocots**:
- Monocots lack cambium tissue, which means they cannot produce the necessary vascular connections needed for grafting to succeed.
- Without cambium, the tissues cannot regenerate and integrate, leading to graft failure.

6. **Conclusion**: The successful grafting in dicots, as opposed to monocots, is primarily due to the presence of cambium tissue that allows for secondary growth and tissue regeneration.

### Final Answer:
Grafting is successful in dicots but not in monocots because dicots have **cambium for secondary growth**.

---