BIOL 142 Chapter 33 Study Guide for TEST 3-2

BIOL 142 Chapter 33 - Phylum Cnidarians = jellyfish two distinct tissue layers no organs capture prey using tentacles with nematocysts 2 basic body

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
BIOL 142: Study Guide for TEST # 4 Chapter 33 – Noncoelomates (lack body cavity) = sponges, jellyfish, and simple worms Note: new phylogenies (based on molecular data) divide the Bilateria into 2 major clades: Ecdysozoans grow by molting external skeletons (= Nematodes and Arthropods); Spiralians grow by adding mass to existing bodies (= all other animals) I. Parazoa – multicellular but lack specialized tissues and symmetry Phylum Porifera = sponges ; larvae are free-swimming, adults are sessile; 3 layers of cells – choanocytes on the inside, epithelium on the outside; filter-feeders : water moves in through pores and out through osculum II. Eumetazoa – animals with true tissues and symmetry A. Acoelomates (no body cavity) i. Diploblasts/ Radial symmetry
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Phylum Cnidarians = jellyfish ; two distinct tissue layers, no organs; capture prey using tentacles with nematocysts; 2 basic body plans = polyps and medusae ; internal extracellular digestion in gut ii. Triploblasts a. Radial Symmetry Phylum Ctenophora = comb jellies b. Bilateral Symmetry/ Protostomes Phylum Platyhelminthes = flatworms ; incomplete gut or none at all; no circulatory system; central nervous system with cerebral ganglion; most are hermaphrodites B. Pseudocoelomates/Protostomes (primitive body cavity between mesoderm and endoderm) – All are triploblasts with bilateral symmetry Phylum Nematoda – Ecdysozoans, true muscles; lack specialized respiratory systems; well-developed digestive system; separate sexes...
View Full Document

This note was uploaded on 09/18/2011 for the course BIO 142 taught by Professor Jarrell during the Spring '11 term at Delgado CC.

Ask a homework question - tutors are online