Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?

Options

A. Phytoplankton
B. Fish
C. Zooplankton
D. Frog

Answer

To answer the question, "Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?", we can follow these steps:

### Step 1: Understand Trophic Levels
Trophic levels refer to the position an organism occupies in a food chain. The primary levels are:
- **Producers** (e.g., phytoplankton)
- **Primary Consumers** (e.g., zooplankton)
- **Secondary Consumers** (e.g., small fish that eat zooplankton)
- **Tertiary Consumers** (e.g., larger fish that eat smaller fish)

### Step 2: Identify Organisms in a Pond Ecosystem
In a pond ecosystem, various organisms can be found, including:
- Phytoplankton (producers)
- Zooplankton (primary consumers)
- Fish (which can be primary and secondary consumers)

### Step 3: Determine Which Organisms Occupy Multiple Trophic Levels
Among the organisms in a pond, fish are notable because:
- They can feed on phytoplankton, making them primary consumers.
- They can also feed on zooplankton or smaller fish, making them secondary consumers.

### Step 4: Conclusion
Based on the analysis, fish are the organisms that occupy more than one trophic level in a pond ecosystem. Therefore, the correct answer to the question is **fish**.

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