PGA as the first `CO_(2)` fixation product was discovered in photosynthesis of

Options

A. Angiosperm
B. Alga
C. Bryophyte
D. Gymnosperm

Answer

To answer the question about PGA (phosphoglyceric acid) as the first CO₂ fixation product discovered in photosynthesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding PGA**:
- PGA stands for phosphoglyceric acid, which is a three-carbon compound formed during the process of photosynthesis.

2. **Historical Context**:
- The discovery of PGA as the first product of CO₂ fixation is attributed to the research conducted by Melvin Calvin.

3. **Experimental Setup**:
- Melvin Calvin conducted experiments using photosynthetic algae. He utilized carbon-14, a radioactive isotope, to trace the path of carbon during photosynthesis.

4. **Findings**:
- Through his experiments, Calvin found that the first stable product formed when CO₂ was fixed during photosynthesis in these algae was phosphoglyceric acid (PGA).

5. **Conclusion**:
- Therefore, the correct answer to the question is that PGA was first discovered in the photosynthesis of algae.

### Final Answer:
PGA as the first CO₂ fixation product was discovered in the photosynthesis of **algae**.

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