An alga as the source of protein is

Options

A. Chlorella
B. Nostoc
C. Spirogyra
D. Ulothrix

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for an alga that serves as a source of protein.

2. **Review the Options**: The options provided are:
- Chlorella
- Nostoc
- Spirogyra
- Ulothrix

3. **Evaluate Each Option**:
- **Chlorella**: This is a unicellular, non-flagellated alga known for being rich in protein. It is often used as a dietary supplement and is even consumed by astronauts due to its high protein content.
- **Nostoc**: This is a cyanobacterium (often referred to as blue-green algae). While it has the ability to fix nitrogen, it is not particularly rich in protein.
- **Spirogyra**: This is a filamentous green alga with ribbon-shaped chloroplasts. It is not specifically known for its protein content.
- **Ulothrix**: This is also a filamentous green alga. While it can be consumed, it is not as widely recognized for its protein content as Chlorella.

4. **Conclusion**: After evaluating all the options, Chlorella stands out as the best source of protein among the listed algae.

5. **Final Answer**: The correct answer is **Chlorella**.

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