Classification
Subject:
Lower Invertebrate Phyla Porifera Cnidaria Platyhelmenthes Nematoda Representative Animal Sponges Jellyfish Tapeworms Roundworm Types of Symmetry No Symmetry Radial Symmetry Bilateral Symmetry Bilateral Symmetry Body Plan 2 cell layers Polyp or Medusa Shape; 2 germ layers 3 Germ layers, true organs, anterior end 3 germ layers; non-segmented, covered by cuticle Digestion Filter nutrients through spongocoel Extracellular ? in gastrovascular cavity Digestive Cavity- branched throughout body Complete digestive tract Method of Transport Sessile Contraction of cells controlled by nerve net Cilia Parapodia Method of Gas Exchange Pores Single entrance for transport of nutrients and gases Body cells have direct contact to outside O2
