Question

When a big fish eats a small fish, which eats water flea supported by phytoplankton water fleas are
A. Producers
B. Primary consumers
C. Secondary consumers
D. Top consumers

Answer 1

Hint: Every living organism on earth depends on and interacts with other living and nonliving things to stay alive. Organisms depend on other organisms for food for example, and also depend on their environment for protection and place to stay.

Complete answer:
In an ecological pyramid, the plants are producers. They are the first trophic level of a pyramid. The primary consumers eat producers. They are the second trophic level of a pyramid. The secondary consumers eat primary consumers. They are the third trophic level of a pyramid. In a water ecosystem, big fish eats a small fish which eats water fleas supported by phytoplankton. In this, phytoplankton are producers, water fleas are primary consumers, small fishes are secondary consumers and big fishes are top consumers.

Thus from the above discussion it can be concluded that the correct answer is option B( Primary consumers).

Additional Information: The structure of the ecosystem can be visualised with ecological pyramids, which were first described by a pioneering study of Charles Elton in the 1920s. Ecological pyramids show the relative amount of various parameters across trophic levels. A trophic level is the group of organisms within an ecosystem which occupy the same level in the food chain. there are five main trophic levels within the food chain, each of which differs in its nutritional value with the primary energy source.

Note: First trophic level is always produced as they have the ability to trap sunlight and manufacture their own food. Second trophic level is herbivores which we call plant eaters.