Bacteria that must have organic molecules both for energy and as a source of carbon are called :

Options

A. chemoheterotrophs
B. chemoautotrophs
C. photoheterotrophs
D. photoautotrophs

Explanation

To solve the question regarding the type of bacteria that must have organic molecules both for energy and as a source of carbon, we can follow these steps:

### Step 1: Understand the Definitions
- **Autotrophs**: Organisms that can produce their own food from inorganic substances (e.g., plants).
- **Heterotrophs**: Organisms that cannot synthesize their own food and must obtain it from other sources (e.g., animals, fungi).

### Step 2: Analyze the Options
1. **Chemoheterotrophs**: These organisms obtain both energy and carbon from organic molecules.
2. **Chemoautotrophs**: These organisms obtain energy from inorganic compounds and can synthesize their own food.
3. **Photoheterotrophs**: These organisms use light for energy but require organic compounds for carbon.
4. **Photoautotrophs**: These organisms use light and inorganic substances to produce their own food.

### Step 3: Identify the Correct Answer
- The question specifies bacteria that require organic molecules for both energy and carbon. This definition fits **Chemoheterotrophs**, as they rely on organic compounds for both energy and carbon sources.

### Conclusion
The correct answer to the question is **Chemoheterotrophs**.

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