Zoology for UPSC and State PSC exams
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Asexual Reproduction: Binary Fission Division of an individual into approximately 2 equal parts.Karyokinesis followed by Cytokinesis.Division might occur across transverse, longitudinal, oblique or any plane.Some organelles from the parent are…
HolophyticNutrition Phytoflagellates possessing Chloroplasts or Chromatophores synthesize their food by photosynthesis.Carbon Dioxide and Water act as raw materials and to enter a complex cycle of chemical reactions and produce Dextrose…
Locomotor organelles found in Protozoa: Pseudopodia Temporary structures formed by streaming flow of cytoplasm (false feet) LobopodiaLobe like Pseudopodia with broad and rounded ends composed of both ectoplasm and endoplasmMove…
First metazoans were most likely radial animals.Believed that bilateral symmetry evolved in radial ancestor when it started creeping. CtenophorePolycladTheory Ctenophores provided a bridge or intermediate forms between radiate coelenterateancestors and…
Radiata Bilateria Body radially or bi-radially symmetricalOrgan systems are incipient and not well markedDiploblastic. Mesoderm is not well developedCoelomic cavity invariably absentMouth is the principal opening of digestivecavityTentacles with nematocystsComb…
Symmetry in general sense can simply be defined as an arrangement of parts of a body or a shape into geometrical designs such that the body is divisible into proportionate…
Lower Invertebrates Higher Invertebrates Generally small in sizeSimple body organisationRadial, bi-radial or no symmetryGerm Layers 2 or 3 (diplo / triploblastic)No Coelom or Pseudocoelom is presentNo separate mouth and anusNo…
The word Onychophora is derived from ancient Greek words “onyches” meaning ‘claws’ and “pherein” meaning ‘to carry’. Onychophora is, therefore, a phylum of elongate, soft-bodied, claw-bearing, vermiform animals. The external morphology…
Major and Minor Phyla All the identified species of animals are divided into a number of phlya (singular: phylum). These phyla are further divided broadly into 2 broad categories: major…