Meristem is :-

Options

A. Specialised region of active cell division
B. Specialised region of active cell differentiation
C. Specialised region of active cell elongation
D. Specialised region of cell matuation

Answer

### Step-by-Step Solution:

1. **Definition of Meristem**:
- Meristem refers to a specialized region in plants where cells are actively dividing. These cells are known as meristematic cells.

2. **Characteristics of Meristematic Cells**:
- Meristematic cells have thin cell walls and are undifferentiated, meaning they have not yet specialized into specific types of cells.

3. **Location of Meristem**:
- Meristematic cells are found in specific regions of the plant, commonly referred to as the meristematic region. This is where active cell division occurs.

4. **Distinction from Other Plant Regions**:
- It is important to differentiate meristematic regions from other regions in the plant:
- **Region of Maturation**: This is where cells differentiate and mature into specific cell types and tissues.
- **Region of Elongation**: This is where cells grow in size but are not necessarily dividing.

5. **Conclusion**:
- Therefore, the correct definition of meristem is that it is a specialized region of active cell division.

### Final Answer:
Meristem is a specialized region of active cell division in plants, consisting of undifferentiated cells with thin cell walls.