Porphyra and Polysiphonia belong to -

Options

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

Answer

To determine which class Porphyra and Polysiphonia belong to, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organisms**: We have two algae: Porphyra and Polysiphonia.

2. **Understand Algae Classification**: Algae are classified into several groups based on their pigments and other characteristics. The main classes of algae include:
- **Chlorophyceae**: Green algae
- **Rhodophyceae**: Red algae
- **Xanthophyceae**: Yellow-green algae
- **Pheophyceae**: Brown algae

3. **Determine the Characteristics of the Given Algae**:
- **Porphyra**: This is commonly known as a type of red algae.
- **Polysiphonia**: This is also recognized as a red algae.

4. **Classify the Algae**: Since both Porphyra and Polysiphonia are identified as red algae, they belong to the class **Rhodophyceae**.

5. **Conclusion**: Therefore, the correct answer is that Porphyra and Polysiphonia belong to **Rhodophyceae**.

### Final Answer:
Porphyra and Polysiphonia belong to the class **Rhodophyceae**.

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