Food chains and food webs help ecologists visualize what is happening within an ecosystem. A food chain helps realize a single thread within a food web.  A food chain also shows where the most biomass in an ecosystem exists, as the start of the food chain, or the base organism, usually has the most biomass (producers, decomposers) since approximately 10% of the biomass from each level is converted to biomass at the next trophic level.  A food web reflects the multiple feeding relationships among organisms in the larger ecosystem. Organisms (consumers) may feed from more than one tropic level and on different types of organisms, which a food web demonstrates.