Azospirillum is a

Options

A. Free-living , nitrogen - fixing eukaryotic microbe
B. symbiotic, nitrogen-fixing eukaryotic microbe
C. free-living , nitrogen -fixing prokaryotic microbe
D. symbiotic, nitrogen - fixing prokaryotic microbe

Answer

To determine what Azospirillum is, we need to analyze the options provided and understand the characteristics of this microbe.

### Step 1: Identify the characteristics of Azospirillum
- Azospirillum is known to be a nitrogen-fixing microbe. Nitrogen fixation is the process of converting atmospheric nitrogen (N₂) into ammonia (NH₃), which can be utilized by plants.
- It is important to note that nitrogen fixation is primarily carried out by prokaryotic organisms, which include bacteria.

### Step 2: Determine if Azospirillum is free-living or symbiotic
- Azospirillum is classified as a free-living nitrogen-fixing bacterium. This means that it does not form a symbiotic relationship with plants but can still fix nitrogen independently in the soil.

### Step 3: Classify Azospirillum as prokaryotic or eukaryotic
- Azospirillum is a prokaryotic organism. Prokaryotes are single-celled organisms that lack a nucleus, and they include bacteria and archaea.

### Conclusion
Based on the characteristics identified, we can conclude that Azospirillum is a **free-living nitrogen-fixing prokaryotic microbe**.

### Final Answer
Azospirillum is a **free-living nitrogen-fixing prokaryotic microbe**.

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