NEET BIOLOGY UNIT 15 ANIMAL KINGDOM ANIMAL - CLASSIFICATION (PORIFERA TO ECHINODERMATA) BRIEF HISTORY OF ANIMAL TAXONOMY TAXONOMY Taxonomy is the branch which deals with the study of nomenclature, classification and their principles. Three steps: (1) Identification (2) Nomenclature (3) Classification Taxonomy word was given by “Candole. It is a Greek word. Taxis - arrangements (systematics) Nomos - Law / Rules (A) Division Radiata - (i) Diploblastic / Triploblastic (ii) Radial symmetry is found, body is bilayered and tissue-grade. (iii) Mouth and digestive cavity present - Coelentron / Gastrovascular cavity (iv) Anus absent i.e. alimentry canal incomplete. Radiata includes two phyla - (i) Cnidaria or Coelenterata (eg. Hydra) - Diploblastic, radial (ii) Ctenophora (e.g. Beroe) - Triploblastic, biradial (According to modern view.) 1. All members are marine. 2. These are of moderate shape and upto 1 m in length. 3. Body is rase or bell or cup-shaped. 4. Endoskeleton is made ...
