Which one is a source of single cell protein ?
(A) Nostoc (B) spirulina (C ) Chlorella (D) Scenedesmus

Options

A. A and B
B. B and C
C. C and D
D. B,C,D

Answer

To determine which option is a source of single cell protein, we need to analyze each of the given options:

1. **Understanding Single Cell Protein (SCP)**: Single cell protein refers to protein derived from unicellular organisms, such as bacteria, yeast, and algae. These organisms can be cultivated and harvested for their protein content.

2. **Analyzing the Options**:
- **(A) Nostoc**: This is a genus of cyanobacteria (blue-green algae). While it is a unicellular organism, it is not primarily known for being a source of protein.
- **(B) Spirulina**: This is a type of blue-green algae (cyanobacteria) that is well-known for its high protein content and is often used as a dietary supplement. It is considered a source of single cell protein.
- **(C) Chlorella**: This is a green microalga that is also rich in protein and is used as a dietary supplement. It is another source of single cell protein.
- **(D) Scenedesmus**: This is a genus of green algae that is primarily multicellular and not typically recognized as a source of single cell protein.

3. **Conclusion**: Based on the analysis, both Spirulina (B) and Chlorella (C) are sources of single cell protein. Therefore, the correct answers are (B) Spirulina and (C) Chlorella.

### Final Answer:
The sources of single cell protein are (B) Spirulina and (C) Chlorella.

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