Which one has oil and occasionally starch as reserve food ?

Options

A. Chlorophyceae
B. Phaeophyceae
C. Rhodophyceae
D. Xanthophyceae.

Answer

To solve the question "Which one has oil and occasionally starch as reserve food?", we will analyze the options provided one by one.

### Step-by-Step Solution:

1. **Identify the Groups**: The options given are:
- Chlorophyceae (Green Algae)
- Pheophyceae (Brown Algae)
- Rhodophyceae (Red Algae)
- Xanthophyceae (Yellow-Green Algae)

2. **Analyze Chlorophyceae**:
- Chlorophyceae, or green algae, contain chlorophyll a, b, and carotenoids.
- Their reserve food is primarily in the form of starch.
- **Conclusion**: This group does not fit the criteria of having oil and occasionally starch.

3. **Analyze Pheophyceae**:
- Pheophyceae, or brown algae, contain the pigment fucoxanthin.
- Their reserve food is mainly in the form of mannitol or laminarian.
- **Conclusion**: This group does not fit the criteria either.

4. **Analyze Rhodophyceae**:
- Rhodophyceae, or red algae, have the pigment phycoerythrin.
- Their reserve food is in the form of Floridian starch, which is similar to amylopectin but more branched.
- **Conclusion**: This group does not fit the criteria.

5. **Analyze Xanthophyceae**:
- Xanthophyceae, or yellow-green algae, primarily contain oils as their major reserve food material.
- They can also have starch, but it is mentioned that starch is present occasionally.
- **Conclusion**: This group fits the criteria of having oil and occasionally starch as reserve food.

6. **Final Answer**: Based on the analysis, the correct answer is **Xanthophyceae**.