The trophic level of S-bacteria and cyanobacteria is
Producer
Consumer
Saprotrophic decomposer
Phagotroph
In tropical rain forest most of the energy in ecosystem flows through
Nektons are
Trees $\rightarrow$ Birds $\rightarrow$ Lice $\rightarrow$ Bacteria. Thus food chain is
When food energy passes from herbivores to carnivores
In a biotic community, primary consumers are