Inclusion bodies of blue-green,purple and green photosynthetic bacteria are:

Options

A. Contractile vacuoles
B. Gas vacuoles
C. Centrioles
D. Microtubules

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the inclusion bodies found in blue-green, purple, and green photosynthetic bacteria. Inclusion bodies are specialized structures within cells that serve specific functions.

2. **Evaluating the Options**:
- **Option A: Contractile Vacuole**: Contractile vacuoles are involved in osmoregulation, helping to maintain water balance within cells. However, they are not classified as inclusion bodies in the context of photosynthetic bacteria.
- **Option B: Gas Vacuole**: Gas vacuoles are indeed inclusion bodies found in certain bacteria, including blue-green (cyanobacteria), purple, and green photosynthetic bacteria. They help the bacteria maintain buoyancy in aquatic environments, allowing them to position themselves optimally for light absorption.
- **Option C: Centrioles**: Centrioles are organelles that play a role in cell division and organization of microtubules, but they are not inclusion bodies and are not specifically related to photosynthetic bacteria.
- **Option D: Microtubules**: Microtubules are structural components of the cytoskeleton in eukaryotic cells, made of tubulin proteins. They do not qualify as inclusion bodies in the context of the question.

3. **Conclusion**: Based on the evaluation of the options, the correct answer is **Option B: Gas Vacuole**. These vacuoles are crucial for the buoyancy of blue-green, purple, and green photosynthetic bacteria.

**Final Answer**: Gas Vacuole (Option B)

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