Plants that have mutualistic relations with nitrogen-fixing bacteria receive from the bacteria

Options

A. ammonium
B. amino acids
C. nitrate
D. nitrite

Answer

### Step-by-Step Solution:

1. **Understanding Nitrogen Fixation**:
- Nitrogen fixation is the process through which atmospheric nitrogen (N₂) is converted into a usable form for plants. This process is crucial because plants cannot utilize atmospheric nitrogen directly.

2. **Role of Nitrogen-Fixing Bacteria**:
- Certain bacteria, such as Rhizobium, have the ability to fix nitrogen. These bacteria often form a mutualistic relationship with leguminous plants (like peas, beans, and clover).

3. **Formation of Nodules**:
- In this mutualistic relationship, the nitrogen-fixing bacteria attach themselves to the roots of leguminous plants. They form specialized structures called nodules.

4. **Conversion of Nitrogen to Ammonia**:
- Inside these nodules, the bacteria convert atmospheric nitrogen into ammonia (NH₃). This conversion is essential as ammonia is a form of nitrogen that plants can utilize.

5. **Utilization of Ammonia by Plants**:
- The ammonia produced by the bacteria is then absorbed by the plant roots and used for various metabolic processes, including the synthesis of amino acids and proteins, which are vital for plant growth and development.

6. **Conclusion**:
- Therefore, the correct answer to the question is that plants with mutualistic relationships with nitrogen-fixing bacteria receive ammonia from the bacteria.

### Final Answer:
Plants that have mutualistic relationships with nitrogen-fixing bacteria receive **ammonia** from the bacteria.

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