A prokaryotic autotrophic nitrogen fixing symbiont is found in

Options

A. Alnus
B. Cycas
C. Cicer
D. Pisum

Answer

To answer the question, "A prokaryotic autotrophic nitrogen-fixing symbiont is found in," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Terms**:
- **Prokaryotic**: Refers to organisms that do not have a defined nucleus, such as bacteria.
- **Autotrophic**: Organisms that can produce their own food, usually through photosynthesis or chemosynthesis.
- **Nitrogen-fixing**: The process by which nitrogen in the atmosphere is converted into ammonia or related compounds in soil and water.
- **Symbiont**: An organism that lives in close association with another organism, often benefiting from the relationship.

2. **Identify the Organism**:
- The question refers to a prokaryotic autotrophic nitrogen-fixing symbiont. One of the well-known groups of bacteria that fit this description is **Cyanobacteria**.

3. **Determine the Host Plant**:
- Cyanobacteria often form symbiotic relationships with certain plants. A notable example is with the plant **Cycus** (a type of cycad).

4. **Cycus and Cyanobacteria**:
- In the roots of Cycus, cyanobacteria can be found, which fix nitrogen and provide it to the plant. This relationship is beneficial for both the cyanobacteria (which get nutrients from the plant) and the Cycus (which gets fixed nitrogen).

5. **Conclusion**:
- Therefore, the answer to the question is that a prokaryotic autotrophic nitrogen-fixing symbiont is found in **Cycus**.

### Final Answer:
A prokaryotic autotrophic nitrogen-fixing symbiont is found in **Cycus**.

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