Give the biological names of the following:
A symbiotic nitrogen fixing bacterium found in root nodules.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the biological name of a symbiotic nitrogen-fixing bacterium found in root nodules.

2. **Identifying Symbiotic Bacteria**: Symbiotic bacteria are those that live in close association with another organism, benefiting both parties. In this case, we are looking for a bacterium that helps in nitrogen fixation.

3. **Recognizing the Role of Nitrogen-Fixing Bacteria**: Nitrogen-fixing bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃), which can be utilized by plants. This process is crucial for plant growth and soil fertility.

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