Overview of Animal Classification: Protozoa, Porifera, Cnidaria, Platyhelminthes, Nematoda, Study notes of Zoology

Download Overview of Animal Classification: Protozoa, Porifera, Cnidaria, Platyhelminthes, Nematoda and more Study notes Zoology in PDF only on Docsity! Animalia Phyla  Protozoa o Microscopic, single celled organism o Exists in colonies also  Colonial protozoa = volvox  Porifera o Simplest, multicellular phylum o Sponges o Made of protein base and crystalline material o Cell specialization but no tissues  Porocyte—creates pore in sponge  Food particles enter through pores, water exits  Coanocyte—collar cell; flagellum draws in food particles and water  Food is then phagotized or transferred to amoebocyte  Amoebocyte—carries food particles to other cell sites; synthesizes protein and crystalline structure  Epidermal cell—creates outer covering  Cnidaria o First multicellular phylum with true tissues  Diploblastic o Jellyfish, anemones, corals, hydra o Gets nutrients through diffusion (body covering is thin) o Body plan  Radial symmetry (round)  Combined mouth/anus  Dimorphism  Polyp  Medusa o Cell types  Muscle  Nerve  Digestive  Reproductive  Sting cells—nematocysts  Platyhelminthes o Tissue specialization  First triploblastic o Flatworms, tapeworms, planaria, flukes o Body plan  Large, flat body  Combined mouth/anus  Branched digestive tract; nutrients diffuse into cells o First phylum to show bilateral symmetry  Allows for oriented (directed) movement  Leads to cephalization creation of a head  Anterior (head)—concentration of sense organs  Posterior (tail end)  Nematoda o True tissues o Round worms o Body plan  Body too thick for diffusion  First system to transport nutrients throughout body  Muscle layer transports nutrients o Pseudocoelomic cavity—muscle not completely lined by tissue on all sides  More flexible  First complete digestive tract  Specialized parts  more efficient digestion o No circulatory or respiratory system o Little cephalization  Mollusca o “soft body” o Snails, clams, oysters, squid, octopi o Most common phylum other than arthropoda o Body plan  Muscular foot to move  Visceral organ mass above foot  Set of tissue around mass that secretes shell  In 0, 1, 2, or 8 parts