In a dicot root , vascular cambium is

Options

A. Completely primary in origin
B. Partly primary and partly secondary
C. Completely secondary in origin
D. None of these

Answer

To solve the question regarding the nature of vascular cambium in a dicot root, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Vascular Cambium**:
- Vascular cambium is a type of lateral meristem that contributes to the secondary growth in plants. It is responsible for the production of secondary xylem (wood) and secondary phloem (bark).

**Hint**: Remember that vascular cambium is crucial for the growth in thickness of stems and roots.

2. **Identifying the Origin**:
- In dicots, the vascular cambium can be classified based on its origin. It can be primary (originating from the apical meristem) or secondary (arising from the lateral meristem).

**Hint**: Differentiate between primary and secondary origins of cambium based on their developmental sources.

3. **Vascular Cambium in Dicot Roots**:
- In dicot roots, the vascular cambium is primarily secondary in origin. This means it develops from the existing tissues rather than from the apical meristem.

**Hint**: Focus on the fact that in dicot roots, the cambium is not derived from the initial growth but rather from the lateral meristem.

4. **Types of Cambium**:
- The cambium found between xylem and phloem in the vascular bundles is called intrafascicular cambium, which is primary. However, the cambium that forms in the region between the vascular bundles in dicot roots is known as interfascicular cambium, which is secondary.

**Hint**: Remember the distinction between intrafascicular (primary) and interfascicular (secondary) cambium.

5. **Conclusion**:
- Based on the above points, we conclude that in a dicot root, the vascular cambium is completely secondary in origin.

**Hint**: Summarize that the correct answer reflects the secondary nature of vascular cambium in dicot roots.

### Final Answer:
In a dicot root, the vascular cambium is completely secondary in origin.