Chemosynthetic autotrophic bacteria :

Options

A. are Nitrocystis and Anabaena
B. play great role in recycling of minerals
C. are important decomposers
D. more than one option is correct

Answer

**Step-by-Step Solution:**

1. **Understanding Chemosynthetic Autotrophic Bacteria**:
- Chemosynthetic autotrophic bacteria are organisms that obtain energy by oxidizing inorganic substances, such as hydrogen sulfide or ammonia, and use this energy to convert carbon dioxide into organic compounds.

2. **Analyzing the Given Options**:
- The question provides several options related to the role of chemosynthetic autotrophic bacteria. We need to evaluate each option to determine which one correctly describes their function.

3. **Evaluating Option 1: Nitrocystis and Anabena**:
- Nitrocystis and Anabena are mentioned in the first option. These are free-living, non-symbiotic bacteria. Since they do not specifically represent chemosynthetic autotrophic bacteria, this option is incorrect.

4. **Evaluating Option 2: Recycling of Minerals**:
- The second option states that chemosynthetic autotrophic bacteria play a great role in the recycling of minerals. This is true, as these bacteria help in the biogeochemical cycles by converting inorganic materials into forms that can be utilized by other organisms. Therefore, this option is correct.

5. **Evaluating Option 3: Important Decomposers**:
- The third option claims that chemosynthetic autotrophic bacteria are important decomposers. This is incorrect because decomposers break down organic matter, while chemosynthetic bacteria primarily utilize inorganic substances for energy.

6. **Evaluating Option 4: More than One Option is Correct**:
- The last option suggests that more than one option is correct. Since we have established that only the second option is correct, this option is also incorrect.

7. **Conclusion**:
- After evaluating all options, the correct answer is that chemosynthetic autotrophic bacteria play a significant role in the recycling of minerals.

**Final Answer**: The correct option is the second one: "They play a great role in the recycling of minerals."

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