Consider a food chain of the following: Fish, crab, phytoplankton, shark. Arrange the above chain in the proper order of trophic level.


This trophic level is a depiction of the pond ecosystem.


The first level is represented by the producers or the autotrophs; for example, phytoplankton and plants. They prepare their own food with the help of energy from sunlight through the process of photosynthesis.


The second trophic level is characterized by the presence of primary consumers such as crabs inhabiting the pond. Organisms in this level consume the phytoplanktons or producers.


The third level comprises of the omnivores, especially the fish species, which can feed on both plants.


The fourth and the top most level is for carnivores or tertiary consumers which are flesh eaters.


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