Plants are called as_________ because they fix carbon dioxide.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Role of Plants:** Plants are essential components of ecosystems as they produce their own food. This ability is crucial for their survival and for the survival of other organisms that depend on them.

2. **Photosynthesis Process:** The process by which plants produce their food is called photosynthesis. During photosynthesis, plants take in carbon dioxide (CO2) from the atmosphere and, using sunlight and chlorophyll, convert it into glucose (a form of sugar) and oxygen.

3. **Definition of Autotrophs:** Because plants can produce their own food using inorganic substances (like carbon dioxide and water), they are classified as autotrophs. Autotrophs are organisms that can create their own food from simple substances.

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