an ecosystem contains a large community of / large numbers of living organisms
group_of_living_organisms is group_of_living_things. multicellular_organism is living_organism. earth has many_different_living_organisms group_of_animals is group_of_living_organisms. large_living_organisms_tend_to has more_mass_than_smaller_ones ecosystem is structure. biome is ecosystem. ecosystem is system. multicellular_algae is multicellular_organism. population is group_of_living_organisms.