Flatworms Platyhelminthes
Flatworms Simplest animals with organ systems Three primary tissue layer Ectoderm, endoderm, mesoderm Bilateral Cephalization No coelom
Turbellarians Digestive system – pharynx, branching gut Ex: Planarian enzymes secreted first Ex: Planarian Nervous system – ganglia, nerve cords, eye spots Respond in cordinated fashion
Excretory – flame cells remove unwanted liquids, passed thru ducts to pores on surface Circulation – diffusion Respiration - diffusion
Reproduce sexually (hermaphrodites) Asexually - regeneration
Cestoda and Trematoda Tapeworms and fluke, respectively Parasitic Lost gut in mouth, habitat rich in predigested food Complex life cycle – sexual and asexual with multiple hosts