The organisms that produce their food by using energy from chemical reaction and not by using sunlight are known as _________ .

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term used to describe organisms that produce their own food using energy derived from chemical reactions instead of sunlight.

2. **Defining Key Terms**:
- **Autotroph**: This term refers to organisms that can produce their own food. They do not rely on other organisms for nutrition.
- **Chemo**: This prefix indicates that the energy source is derived from chemical reactions.

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