BIO 200 Lecture Notes - Lecture 20: Notochord, Crinoid, Water Vascular System
31 Oct 2016
School
Department
Course
Professor
Document Summary
Echinoderms & hemichordates: echinoderms are the first deuterostome, pentaradial symmetry and endoskeleton, the water vascular system and tube feet, echinoderm regeneration and reproduction, three groups of echinoderms, hemichrodates: acorn worms. Chordates traits and non-vertebral chordates: what makes a chordate, urochordates: tunicates, cephalochordates: lancelets. Ancestral deuterostomes have traits we see in modern echinoderms and chordates. Penta radial symmetry: there are five axes of symmetry: example: star fish, sand dollar, starfish larvae. Echinoderms are characterized by an internal skeleton: means spiny skin. Echinoderms have a water vasculature system and tube feet: feeding, gas exchange, and locomotion. Echinoderms are characterized by their oral and aboral surfaces: oral: underneath. Echinoderms have asexual and sexual reproduction: form of regeneration. There are 20 extinct classes of echinoderms, but only 3 extant groups: crinoids, Echinozoans, and asterozoans: the crinoids differ in their ability to move, the echinozoans have no arms.
