Sec 4 Worms Flatworms – Are flat and soft as jelly – Parasite is an organism that lives inside or on another organism – Host is the organism in or on which it lives; parasites may rob their hosts of food and make them weak; they may injure the hosts tissues or organs, but they rarely kill their host (example: flukes & tapeworms) – Free-living organism does not live in or on other organisms; they may glide over rocks in ponds, slide over damp soil, or swim slowly through the ocean like ruffled brightly patterned leaves