Ribbon-like acoelomates with bilateral symmetry are examples of _________ ? A. Cnidarians: jellyfish B. Platyhelminthes: flat worms C. Nemotoda: round worms D. Mollusca: mollusks E. Annelida: segmented worms
B. Platyhelminthes: flat worms. They have 3 germ layer; Organ level organization; Sac body; Incomplete digestive system; there are 20,000 species of flatworm - free living, parasitic.
