Which of the following is a non-symbiotic nitrogen fixing prokaryote?

Options

A. Azotobacter
B. Clostridium
C. Beijerinckia
D. all of these

Explanation

To solve the question "Which of the following is a non-symbiotic nitrogen-fixing prokaryote?", follow these steps:

### Step 1: Understand the Terms
- **Non-symbiotic**: This refers to organisms that do not have a mutual relationship where they depend on each other for survival or benefit.
- **Nitrogen-fixing**: This is the process by which nitrogen in the atmosphere is converted into ammonia or related compounds in soil, making it accessible to plants.
- **Prokaryote**: These are single-celled organisms that lack a defined nucleus, such as bacteria.

### Step 2: Identify the Options
- Review the options provided in the question (though not listed here, we assume they include various prokaryotic organisms).

### Step 3: Analyze Each Option
- **Azotobacter**: This is an aerobic bacterium that fixes nitrogen and is known to be non-symbiotic.
- **Clostridium**: This is an anaerobic bacterium that also fixes nitrogen and is non-symbiotic.
- **B. jyrinchia**: This is another aerobic bacterium that fixes nitrogen and is non-symbiotic.

### Step 4: Determine the Correct Answer
- Since all the mentioned organisms (Azotobacter, Clostridium, and B. jyrinchia) are non-symbiotic nitrogen-fixing prokaryotes, the correct answer would be all of them.

### Conclusion
- Therefore, the answer to the question is **Option D: All of these**.

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