Which type of organism always occurs at the first step in every food chain?

Options

A. heterotroph
B. autotroph
C. saprotroph
D. scavenger

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which type of organism is always found at the first step in every food chain.

2. **Identifying the Options**: We have four options to consider:
- Heterotroph
- Autotroph
- Saprotroph
- Scavenger

3. **Analyzing Heterotrophs**: Heterotrophs are organisms that cannot produce their own food and must consume other organisms (plants or animals) for energy. Therefore, they cannot be at the first step of a food chain.

4. **Analyzing Autotrophs**: Autotrophs are organisms that can produce their own food through processes like photosynthesis. They are typically plants that use sunlight to create energy, making them the primary producers in a food chain. Thus, they are found at the first step.

5. **Analyzing Saprotrophs**: Saprotrophs feed on dead and decaying organic matter. Since they rely on already dead material, they cannot be at the first step in a food chain.

6. **Analyzing Scavengers**: Scavengers consume decaying biomass and are also not found at the first step since they depend on other organisms that have already died.

7. **Conclusion**: Based on the analysis, the correct answer is Autotroph, as they are the organisms that always occur at the first step in every food chain.

**Final Answer**: Autotroph

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