Define the trophic levels and mention the organisms that occupy in each trophic level.

Explanation

### Step-by-Step Solution:

1. **Definition of Trophic Levels**:
- Trophic levels refer to the different stages in a food chain where organisms are classified based on how they obtain energy. Each level represents a step in the flow of energy through an ecosystem.

2. **First Trophic Level - Producers**:
- The first trophic level consists of producers, which are organisms that can produce their own food through photosynthesis.
- **Examples**: Plants, algae, and some bacteria.
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