Identify the incorrect expression from the following statements:

Options

A. Phylloclades of Casuarina are differentiated into nodes and internodes
B. Suckers of Chrysenthemum are differentiated into nodes and internodes
C. Phyllodes of Acacia are differentiated into nodes and internodes
D. Bulb of Onion is differentiated into nodes and internodes

Answer

To identify the incorrect expression from the given statements, we will analyze each statement carefully based on the morphology of flowering plants.

### Step-by-Step Solution:

1. **Understanding the Root and Shoot Systems**:
- The plant is divided into two main systems: the root system (below ground) and the shoot system (above ground).
- The shoot system includes the stem, branches, leaves, and flowers.

2. **Identifying Nodes and Internodes**:
- In the shoot system, the stem has distinct structures known as nodes (points where leaves or branches arise) and internodes (the segments between two nodes).
- This structure is characteristic of stems.

3. **Analyzing the Statements**:
- **Statement 1**: "In the phyloclad of Casuarina, we will find nodes and internodes."
- **Analysis**: This is correct. A phyloclad is a modified stem that carries out photosynthesis and will have nodes and internodes.

- **Statement 2**: "The suckers of the chrysanthemum are also differentiated in the nodes and internodes."
- **Analysis**: This is also correct. Suckers are modified stems that can produce new plants and will have nodes and internodes.

- **Statement 3**: "In the phyllodes of acacia, there will be nodes and internodes."
- **Analysis**: This statement is incorrect. Phyllodes are modifications of the leaf petiole, not the stem. Therefore, they do not have nodes and internodes.

- **Statement 4**: "In the bulb of onion, nodes and internodes will be seen in it."
- **Analysis**: This is correct. The onion bulb is a modified stem that stores food and has nodes and internodes.

4. **Conclusion**:
- The incorrect expression is found in Statement 3 regarding the phyllodes of acacia, as they do not exhibit nodes and internodes due to being a modification of the leaf stalk.

### Final Answer:
The incorrect expression is: **"In the phyllodes of acacia, there will be nodes and internodes."**