Nitrogenase enzyme is produced by:

Options

A. All prokaryotes
B. Some eukaryotes
C. All eukaryotes
D. Some prokaryotes

Answer

**Step-by-Step Solution:**

1. **Understanding Nitrogenase**: The nitrogenase enzyme is crucial for the process of nitrogen fixation, which converts atmospheric nitrogen (N₂) into ammonia (NH₃). This process is essential for making nitrogen available to living organisms.

2. **Identifying the Organisms**: Nitrogenase is produced by certain microorganisms. It is important to differentiate between prokaryotes and eukaryotes in this context. Prokaryotes include bacteria and archaea, while eukaryotes include plants, animals, fungi, and protists.

3. **Prokaryotic Nitrogen Fixers**: Most nitrogen-fixing organisms are prokaryotes. Examples include:
- **Rhizobium**: A genus of bacteria that forms symbiotic relationships with legumes.
- **Nostoc**: A genus of cyanobacteria that can fix nitrogen.
- **Anabaena**: Another genus of cyanobacteria known for nitrogen fixation.

4. **Conclusion**: Based on the information, nitrogenase is produced by some prokaryotes, specifically certain bacteria that have the capability to fix nitrogen.

5. **Final Answer**: The correct answer to the question "Nitrogenase enzyme is produced by:" is **some prokaryotes**.

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