Which mineral helps the enzyme nitrogenase in nitrogen fixation?

Explanation

**Step-by-Step Solution:**

1. **Understanding Nitrogen Fixation**: Nitrogen fixation is the process by which atmospheric nitrogen (N₂) is converted into ammonia (NH₃), making it usable for plants. This process is essential because plants cannot directly utilize atmospheric nitrogen.

2. **Role of Prokaryotes**: The organisms primarily responsible for nitrogen fixation are prokaryotes, particularly certain bacteria. These bacteria possess the ability to convert atmospheric nitrogen into a form that plants can use.

3. **Enzyme Involved**: The key enzyme that facilitates nitrogen fixation is called nitrogenase. This enzyme is crucial for the reduction of nitrogen gas (N₂) to ammonia (NH₃).

...