Second trophic level in a lake is

Options

A. fishes
B. phytoplankton
C. zooplankton
D. benthos

Answer

To determine the second trophic level in a lake ecosystem, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Trophic Levels**: Trophic levels represent the position of organisms in a food chain. The first trophic level consists of primary producers, which are organisms that produce their own food through photosynthesis or chemosynthesis.

2. **Identify Primary Producers in a Lake**: In a lake ecosystem, the primary producers are typically phytoplankton. These microscopic plants use sunlight to produce energy and form the base of the food web.

3. **Identify Primary Consumers**: The organisms that feed on primary producers are called primary consumers. In the case of a lake, the primary consumers that feed on phytoplankton are zooplankton.

4. **Determine the Second Trophic Level**: Since zooplankton feed on phytoplankton, they occupy the second trophic level in the lake ecosystem. Therefore, zooplankton are classified as primary consumers and represent the second trophic level.

5. **Conclusion**: The second trophic level in a lake ecosystem is occupied by zooplankton.

### Final Answer:
The second trophic level in a lake is **zooplankton**.

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