sentences: algae is a kind of organism
docs: algae is eukaryotic_organism. marine_organism is aquatic_organism. fish is aquatic_organism. seaweed is marine_organism. multicellular_algae is algae. algae is aquatic_organism. green_algae is marine_organism. multicellular_algae is multicellular_organism. freshwater_organism is aquatic_organism. seaweed is algae.