BIOL 2030 Chapter Notes - Chapter 8: Microstructure, Parthenogenesis, Limnognathia
Document Summary
Are worms and (most) have bilateral symmetry and are triploblastic animals. Have acoelomate bodies (lack coelom) and have mesoderm. Have only one internal space (digestive cavity) Parenchyma is the region between the epidermis and the digestive cavity lining. a pseudocoelomate has an internal cavity (pseudocoelom), surrounding the gut, but the cavity is not lined with mesoderm (unlike coelomate animal) Have a distinct anteroposterior axis lack true brain. Clade platyzoa: are a part of lophotrochozoan protosome phyla. Phylum platyhelminthes there are four classes: turbellaria (nonparasitic), trematoda, monogenea, and cestoda (all parasitic) turbellarians have ciliated body ( cellular epidermis with rhabdites) while the parasitic classes have nonciliatd bodies (called syncytial tegument). The parasitic class have a body has a tegument. Have a mouth, pharynx, and intestine (intracellular digestion) Have auricles (earlike lobes), statocysts (balancing organ), rheoreceptors (sensing water current) excretory system comprises two lateral canals with braches bearing flame cells and ocelli (light sensitive eyespot)