Blue green algae are

Options

A. Photo-autotrophs
B. Chemo-autotrophs
C. Photo-heterotrophs
D. Chemo heterotrophs

Answer

**Step-by-Step Solution:**

1. **Understanding Blue Green Algae**: Blue green algae, also known as cyanobacteria, are a type of bacteria that can perform photosynthesis. This means they can convert sunlight into energy to produce their own food.

2. **Identifying the Nutritional Mode**: Blue green algae are classified as autotrophs because they can produce their own food. Autotrophs are organisms that can synthesize their own food from inorganic substances.

3. **Distinguishing Types of Autotrophs**: There are two main types of autotrophs:
- **Photoautotrophs**: These organisms use sunlight as their energy source.
- **Chemoautotrophs**: These organisms derive energy from inorganic chemicals.

4. **Analyzing the Options**:
- **Photoautotrophs**: Since blue green algae use sunlight for photosynthesis, they fall under this category.
- **Chemoautotrophs**: This option is incorrect for blue green algae as they do not produce food from inorganic chemicals.
- **Heterotrophs**: This option is also incorrect because heterotrophs rely on other organisms for food, which blue green algae do not.

5. **Conclusion**: Based on the above analysis, blue green algae are best classified as photoautotrophs.

**Final Answer**: Blue green algae are photoautotrophs.

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