BIOL108 Lecture Notes - Lecture 26: Deuterostome, Symmetry In Biology, Tube Feet

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Lien Luong

Document Summary

Make a table of all phylums, classes, orders, etc. and how they differentiate. Phylum echinodermata sea stars, sea urchins, sea lilies, sea cucumbers. ~7000 extant species calcareous endoskeleton suited to fossilization (contains calcium carbonate) Mouth at centre of arms and faces down. Adults: penta-radial symmetry penta = 5 except for sea cucumbers. Larvae - bilateral symmetry right side is later absorbed. Typically both sexes engage in broadcast spawning fertilization occurs in open water larvae are planktonic (small organisms that drift or swim weakly in a body of water) Water vascular system (all echinoderms) network of hydraulic canals branching into extensions called tube feet madreporite: allows water to flow in and out of system water pressure + adhesive -> operate tube feet (ampulla + podium) Class echinoidea (sea urchins, sand dollars) no arms, slow moving still penta-radial symmetry spines: locomotion and protection eat seaweed.