Which cambium is primary in origin :

Options

A. Intrafascicular cambium
B. Interfascicular cambium
C. Cork cambium
D. Both 1 and 2

Answer

To determine which cambium is primary in origin, we need to analyze the types of cambium mentioned in the question.

### Step-by-Step Solution:

1. **Understanding Cambium Types**:
- Cambium is a type of meristematic tissue responsible for secondary growth in plants.
- There are two main types of cambium: primary and secondary.

2. **Identifying Intrafascicular Cambium**:
- Intrafascicular cambium is located between the xylem and phloem within the vascular bundles.
- It is considered a primary cambium because it arises from the procambium during the early stages of plant development.

3. **Identifying Interfascicular Cambium**:
- Interfascicular cambium is found between the vascular bundles.
- It is formed from the parenchyma cells and is considered a secondary cambium as it develops after the primary growth has occurred.

4. **Identifying Cork Cambium**:
- Cork cambium, also known as phellogen, is responsible for producing the outer protective layer of the plant.
- It is also classified as a secondary cambium because it arises from the pericycle or outer cortex during secondary growth.

5. **Conclusion**:
- Based on the definitions and origins of the cambium types:
- Intrafascicular cambium is primary in origin.
- Both interfascicular cambium and cork cambium are secondary in origin.
- Therefore, the correct answer to the question is **intrafascicular cambium**.

### Final Answer:
The cambium that is primary in origin is **intrafascicular cambium**.