Algae employed by Calvin et al in experiments on photosynthesis belong to

Options

A. Euglena and Scendesmus
B. Chara
C. Chlamydomonas and Chlorella
D. Chlorella and Scenedesmus.

Answer

To answer the question "Algae employed by Calvin et al. in experiments on photosynthesis belong to," we need to analyze the options and the information provided about the experiments conducted by Melvin Calvin and his colleagues.

### Step-by-Step Solution:

1. **Understanding the Context**: The question refers to the experiments conducted by Melvin Calvin, which led to the discovery of the Calvin cycle. This cycle is crucial for understanding how carbon dioxide is fixed during photosynthesis.

2. **Identifying the Algae Used**: According to the information, the primary algae used in Calvin's experiments were Chlorella and Syndesmos. These algae were utilized to study the dark reactions of photosynthesis, where ATP produced during the light reactions is used to form carbohydrates.

3. **Evaluating the Options**:
- **Option 1: Euglena and Syndesmos**: Euglena is not classified as an algae in the context of Calvin's experiments.
- **Option 2: Cara**: This is incorrect as it was not used in these experiments.
- **Option 3: Chlamydomonas and Chlorella**: While Chlorella is correct, Chlamydomonas was not used in Calvin's experiments.
- **Option 4: Chlorella and Syndesmos**: This option is correct as both were indeed used in Calvin's experiments.

4. **Conclusion**: Based on the analysis, the correct answer is **Option 4: Chlorella and Syndesmos**.

### Final Answer:
The algae employed by Calvin et al. in experiments on photosynthesis belong to **Chlorella and Syndesmos**.

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