Which of the following is true regarding chemoautotrophs ?

Options

A. Bacteria oxidise various inorganic substance only for food production.
B. They use chemical energy for food synthesis
C. They use light energy for food production
D. Both (1) & (2)

Answer

### Step-by-Step Solution:

1. **Understanding Chemoautotrophs**: Chemoautotrophs are organisms that obtain energy by oxidizing inorganic substances. They do not rely on sunlight for energy, which distinguishes them from photoautotrophs.

2. **Analyzing the Options**:
- **Option 1**: "Bacteria oxidize various inorganic substances."
- This is true. Chemoautotrophs can oxidize inorganic compounds such as hydrogen sulfide, ammonia, and ferrous iron to obtain energy.

- **Option 2**: "For food production, they use chemical energy."
- This is also true. Chemoautotrophs utilize chemical energy derived from the oxidation of inorganic substances to synthesize organic compounds.

- **Option 3**: "They use both light energy for food production."
- This is false. Chemoautotrophs do not use light energy; this characteristic is specific to photoautotrophs.

3. **Conclusion**: Based on the analysis, both Option 1 and Option 2 are correct statements regarding chemoautotrophs. Therefore, the correct answer is that both statements 1 and 2 are true.

### Final Answer:
Both statements 1 and 2 are true regarding chemoautotrophs.

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