Holdfast, stipe and frond constitute the plant body in case of

Options

A. Rhodophyceae
B. Chlorophyceae
C. Phaeophyceae
D. All of the above

Answer

To solve the question "Holdfast, stipe and frond constitute the plant body in case of," we need to analyze the options provided and identify which group of algae these structures belong to.

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Holdfast**: This is a root-like structure that anchors the plant to a substrate.
- **Stipe**: This is the stem-like structure that supports the fronds.
- **Frond**: This refers to the leaf-like structures of the plant.

2. **Identifying the Groups**:
- The options given are:
- Rhodophyceae (Red algae)
- Chlorophyceae (Green algae)
- Pheophyceae (Brown algae)
- All of the above

3. **Analyzing Pheophyceae**:
- Pheophyceae, or brown algae, are known to have a complex structure that includes holdfasts, stipes, and fronds.
- They are characterized by the presence of the pigment fucoxanthin, which gives them their brown color.

4. **Analyzing Rhodophyceae and Chlorophyceae**:
- Rhodophyceae (red algae) typically do not have a differentiated plant body with these structures.
- Chlorophyceae (green algae) also do not generally exhibit a holdfast, stipe, and frond structure.

5. **Conclusion**:
- Since holdfast, stipe, and frond are specific to Pheophyceae, the correct answer to the question is **Pheophyceae**.

### Final Answer:
The correct answer is **Pheophyceae**.