Nitrogen fixing bacteria convert:-

Options

A. `N_2toNH_3`
B. `NH_4^(+) to Nitrates
C. `NO_2 to NO_3`
D. `NO_3 to N_2`

Answer

**Step-by-Step Solution:**

1. **Understanding Nitrogen Fixation**: Nitrogen-fixing bacteria are microorganisms that convert atmospheric nitrogen (N₂) into a form that plants can use, primarily ammonia (NH₃). This process is crucial for the nitrogen cycle, as most organisms cannot utilize atmospheric nitrogen directly.

2. **Types of Nitrogen-Fixing Bacteria**: There are two main types of nitrogen-fixing bacteria:
- **Free-living bacteria**: These bacteria live independently in the soil and can fix nitrogen without a host plant. Examples include Azotobacter and Clostridium.
- **Symbiotic bacteria**: These bacteria form a mutualistic relationship with certain plants, especially legumes. An example is Rhizobium, which lives in root nodules of legumes.

3. **The Process of Nitrogen Fixation**: The conversion of atmospheric nitrogen to ammonia is facilitated by an enzyme called nitrogenase. This enzyme is produced by nitrogen-fixing bacteria.

4. **Chemical Reaction**: The simplified chemical reaction for nitrogen fixation can be represented as:
\[ N_2 (g) + 8H^+ + 8e^- \rightarrow 2NH_3 (g) + H_2 (g) \]
This shows that atmospheric nitrogen is converted into ammonia.

5. **Conclusion**: Therefore, the primary function of nitrogen-fixing bacteria is to convert atmospheric nitrogen into ammonia, which can then be utilized by plants for their growth and development.

**Final Answer**: Nitrogen-fixing bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃).

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