Cycas and Azolla plants are associated with

Options

A. Bacillus
B. Klebsiella
C. Anabaena
D. Rhizobium

Answer

**Step-by-Step Solution:**

1. **Identify the Plants:** The question asks about the association of Cycas and Azolla plants.

2. **Understand the Association:** Cycas and Azolla are known to have a symbiotic relationship with certain microorganisms.

3. **Recognize the Microorganisms:** The specific microorganisms associated with these plants are cyanobacteria, particularly the genera Anabaena and Nostoc. These are blue-green algae that have nitrogen-fixing capabilities.

4. **Explain the Symbiotic Relationship:** In this symbiotic association, the cyanobacteria live within the tissues of the Azolla plant, providing it with nitrogen in exchange for carbohydrates and a suitable habitat.

5. **Conclusion:** Therefore, Cycas and Azolla plants are associated with nitrogen-fixing cyanobacteria, specifically Anabaena.

**Final Answer:** Cycas and Azolla plants are associated with nitrogen-fixing cyanobacteria, particularly Anabaena.

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