The length of different internodes in a culm of sugarcane is variable because

Options

A. shoot apical meristem
B. position of axillary buds
C. size of leaf lamina at the node below each internode
D. Intercalary meristem

Explanation

### Step-by-Step Solution:

1. **Understanding Plant Structure**:
- In plants, there are different types of meristematic tissues that are responsible for growth. These include apical meristem, lateral meristem, and intercalary meristem.

2. **Identifying the Types of Meristematic Tissue**:
- **Apical Meristem**: Located at the tips of roots and shoots, responsible for vertical growth.
- **Lateral Meristem**: Responsible for the thickness or girth of the plant.
- **Intercalary Meristem**: Found at the base of internodes and responsible for the elongation of internodes.

3. **Focus on Sugarcane**:
- In sugarcane, the internodes are the sections between the nodes. The length of these internodes varies due to the activity of the intercalary meristem.

4. **Role of Intercalary Meristem**:
- The intercalary meristem allows for the elongation of the internodes, which is why different internodes in sugarcane can vary in length. This growth is crucial for the plant's overall height and structure.

5. **Conclusion**:
- The variability in the length of different internodes in a culm of sugarcane is primarily due to the presence and activity of intercalary meristem.

### Final Answer:
The length of different internodes in a culm of sugarcane is variable because of the presence of intercalary meristem.

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