A plot of trophic diversity across the major groups of organisms shows highest trophic diversity amo

Prokaryotes, which have cells with no membrane-bound nucleus or organelles, include both bacteria and the archaea. The archaea are prokaryotes distinguished from bacteria on the basis of structural, physiological, and other biological features. Though first discovered in association with extreme environments, the archaea are now known to be widely spread in the biosphere, particularly in the oceans. The protists are either photosynthetic or heterotrophic, most plants are photosynthetic, and all fungi and animals are heterotrophic. In contrast, the prokaryotes include photosynthetic, chemosynthetic, and heterotrophic species, making them, as a group, the most trophically diverse organisms in the biosphere.