Choose the correct option w.r.t most common nutritional class of bacteria.

Options

A. inorganic (Carbon source) organic (Electron source)
B. Organic (Carbon source) Inorganic (Electron source)
C. Organic (Carbon source) Organic (Electron source)
D. Inorganic (Carbon source) Inorgnic (Electron source)

Answer

To solve the question regarding the most common nutritional class of bacteria, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Nutritional Classes**:
- Bacteria can be classified based on their sources of energy and carbon. The two main energy sources are chemical (chemotrophic) and light (phototrophic).

2. **Energy Source Classification**:
- **Chemotrophic**: Bacteria that obtain energy from chemical compounds.
- **Phototrophic**: Bacteria that obtain energy from light.

3. **Carbon Source Classification**:
- Carbon sources can be categorized into two types:
- **Organic Compounds**: Derived from living organisms.
- **Inorganic Compounds (CO2)**: Carbon dioxide, which is a non-living source.

4. **Common Nutritional Class of Bacteria**:
- Most bacteria are heterotrophic, meaning they primarily use organic compounds as their carbon source.
- They typically obtain energy through the breakdown of these organic compounds (chemotrophic).

5. **Conclusion**:
- The most common nutritional class of bacteria is those that utilize organic compounds as their carbon source and inorganic sources for electrons. Therefore, the answer to the question is that the most common nutritional class of bacteria is heterotrophic, relying on organic compounds.

### Final Answer:
The most common nutritional class of bacteria is heterotrophic, utilizing organic compounds as their carbon source.

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