The correct answer is protozoa the following organisms are located only in the 3rd trophic level of the soil food web.
The trophic level is the first second and third trophic level. Free-living protozoa occupy the trophic levels as primary consumers. Nematodes and grasshoppers are also there, It has producers, consumers, decomposers.
Soil protozoa consist of bare amebae, testate amebae, flagellates, ciliates, microsporidia, and sporozoans. So far, approximately 1600 species were recorded from the soil, lots of that have unique variations to the soil environment. Very likely, the genuine quantity of soil protozoa is lots higher, this is 4000 or greater species.
Thus it is clear that protozoa are located only in the 3rd trophic level of the soil food web.
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