BIOL 1202 : Biology 1202 Exam 4 Notes- All
Document Summary
Asymmetrical body usually with a coiled shell: result of torsion, rotation of the visceral mass. Head surrounded by grasping tentacles: usually with suckers. Shell may be external, internal, or absent. Body is divided into segments: each segment has a set of muscles, contract against coelomic fluid (hydrostatic skeleton) Closed circulatory system with 5 pumping vessels (hearts) Hrudinea (leech: rotifera-parthenogenesis, cnidaria-radial symmetry, polyp and medusa body form, platyhelminthes- flatworms, gastrovascular cavity, porifera-gastrovascular cavity, two tissue layers. Cnidarians use ___________ to immobilize or trap prey: statocysts, gastroderm, mesoglea, cnidocytes. Concept 33. 4: echdysozoans are the most species rich animal group. 2 out of every 3 known species of animals are arthropods. Arthropod body is covered by an exoskeleton made of chitin: when an arthropod grows it sheds the exoskeleton by a process called ecdysis. Arthropods have an open circulatory system: hemolymph is circulated into spaces surrounding tissues. Variety of gas exchange organs: gills, tracheal tissues, book lungs. Body has 2 regions: cephalothorax, abdomen.
