Question

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

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

Answer 1

The Correct Option is B

The Correct option is B: Fish.
In an aquatic ecosystem, fish can consume phytoplankton and other producers. In this context, fish act as primary consumers or herbivores in the grazing food chain. Some larger fish may also prey on smaller fish. Phytoplankton are always producers, while zooplankton are always primary consumers. Frogs function as secondary consumers, feeding on primary consumers such as insects. 
Thus, the correct answer is option B.