Vascular cambium is absent

Options

A. Dicot leaf
B. Monocot stem
C. Monocot root
D. All

Answer

### Step-by-Step Solution:

1. **Understanding Vascular Cambium**:
- Vascular cambium is a type of lateral meristem that is responsible for secondary growth in plants. This growth increases the thickness of stems and roots.

2. **Identifying the Role of Vascular Cambium**:
- In dicots, vascular cambium is present in both the stem and root, allowing for secondary growth. This results in an increase in the lateral thickness of these structures.

3. **Analyzing the Options**:
- The question provides options: monocot leaf, monocot stem, monocot root, and all.
- We need to determine where vascular cambium is absent.

4. **Monocots and Vascular Cambium**:
- In monocots, secondary growth does not occur. Therefore, vascular cambium is absent in monocot stems and roots.

5. **Considering Dicot Leaves**:
- While dicot stems and roots have vascular cambium, dicot leaves do not have vascular cambium either.

6. **Conclusion**:
- Since vascular cambium is absent in monocot stems, monocot roots, and dicot leaves, the correct answer is that vascular cambium is absent in all the given options.

### Final Answer:
- Vascular cambium is absent in monocot leaf, monocot stem, monocot root, and dicot leaf. Therefore, the correct option is **"all"**.

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