Which one of the following is not a lateral meristem

Options

A. Intercalary meristem
B. Intrascicular cambium
C. Interfascicular cambium
D. Phellogen

Answer

To determine which of the following options is not a lateral meristem, we need to understand the definitions and functions of each type of meristem mentioned in the options.

### Step-by-Step Solution:

1. **Understand the Types of Meristems**:
- Meristems are regions of plant tissue that are responsible for growth. They can be classified into two main types: apical meristems and lateral meristems.
- Lateral meristems are responsible for secondary growth, which increases the thickness of the plant.

2. **Identify the Options**:
- **Option A: Intercalary Meristem**: This type of meristem is found at the base of leaves or internodes in grasses and is responsible for the elongation of these parts. It is not classified as a lateral meristem.
- **Option B: Intra-secular Cambium**: This is a lateral meristem that contributes to secondary growth in plants.
- **Option C: Interfasicular Cambium**: This is also a lateral meristem involved in secondary growth, connecting the fascicular cambium in vascular bundles.
- **Option D: Phallogen**: This is a lateral meristem that contributes to the formation of the periderm (cork) in plants.

3. **Analyze Each Option**:
- **Intercalary Meristem (Option A)**: Not a lateral meristem; it is responsible for growth in length rather than thickness.
- **Intra-secular Cambium (Option B)**: A lateral meristem; involved in secondary growth.
- **Interfasicular Cambium (Option C)**: A lateral meristem; involved in secondary growth.
- **Phallogen (Option D)**: A lateral meristem; involved in the formation of protective tissues.

4. **Conclusion**:
- The only option that is not a lateral meristem is **Option A: Intercalary Meristem**.

### Final Answer:
**Option A: Intercalary Meristem** is not a lateral meristem.

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