Consumers are organisms that a. eat only other animal species. b. get solar or other energy indirectly. c. are also known as self-feeders. d. occupy an ecosystem's lowest energy level. 35. the bacteria that live within the roots of a soybean plant are a critical part of the nitrogen cycle because they a. provide the plant with sugars needed for growth. b. transform nitrates into nitrogen gas for release. c. change atmospheric nitrogen into a usable form. d. release nitrogen by decomposing dead plant parts.