Which of the following statement is correct

Options

A. All bacteria are heterotrophic
B. Bacteria are either heterotrophic or chemoautotrophic
C. Bacteria can also be photoautotrophic
D. Bacteria are either photoautotrophic or chemoautotrophic

Explanation

To determine which of the statements regarding bacteria is correct, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Heterotrophic Bacteria**:
- Heterotrophic bacteria are those that cannot synthesize their own food. Instead, they rely on other organisms or dead organic matter for nutrition.
- **Evaluation**: The statement "All bacteria are heterotrophic" is incorrect because not all bacteria fall into this category.

**Hint**: Remember that heterotrophic organisms depend on others for food.

2. **Understanding Chemo-autotrophic Bacteria**:
- Chemo-autotrophic bacteria are capable of synthesizing their own food using chemical reactions, often involving inorganic substances.
- **Evaluation**: The statement "Bacteria are either heterotrophic or chemo-autotrophic" is correct, as it encompasses the ability of some bacteria to produce their own food through chemical means.

**Hint**: Chemo-autotrophs use chemicals, not sunlight, to create energy.

3. **Understanding Phototrophic Bacteria**:
- Phototrophic bacteria can synthesize their own food using sunlight, similar to how plants do through photosynthesis.
- **Evaluation**: The statement "Bacteria can also be phototrophic" is also correct, as some bacteria, like blue-green algae, can perform photosynthesis.

**Hint**: Phototrophic organisms use sunlight for energy.

4. **Conclusion**:
- Based on the evaluations:
- The first statement is incorrect.
- The second statement is correct.
- The third statement is also correct.
- Therefore, the correct options are the second and third statements.

### Final Answer:
The correct statements are:
- Bacteria are either heterotrophic or chemo-autotrophic.
- Bacteria can also be phototrophic.