Content text Zoology Ultra HD Maps.pdf
Chapter Animal Kingdom: Non-Chordates 1A 2 BASIS OF ANIMAL CLASSIFICATION m There are fundamental features common to various individuals and have certain distinct characters which are specific to each phyla/class. m Some Conclusions From Classification: l Platyhelminthes are first triploblastic, bilaterally symmetrical acoelomates. l Poriferans are mostly asymmetrical organisms with cellular level of organisation. l Bilateral symmetry is most advanced form of symmetry that arose with motile organisms. l All diploblastic organisms have radial symmetry and are acoelomates. l Echinoderms have radial symmetry at adult stage and bilateral in the larval stage. Broad Classification Hierarchy Simple Level of Organisation Types of Symmetry Germ Layers Body Cavity/Coelom (mesodermal lining) Phylum(s) Metamerism/ Segmentation Notochord Cellular Asymmetrical Any plane passing through the centre does not divide the organism into 2 equal halves Not specified (loose cell aggregates) Porifera Tissue Radial Any longitudinal plane passing through the central axis of the body divides the organism into 2 identical halves Diploblastic Ectoderm Undifferentiated mesoglea Endoderm Acoelomates (No body cavity) Coelenterata Ctenophora Organ Bilateral Only one longitudinal plane passing through the centre of the body divides the organism into identical right and left halves Triploblastic Ectoderm Mesoderm Endoderm Pseudocoelomate Scattered pouches of mesoderm between ecto and endoderm Aschelminthes Annelida Arthropoda Mollusca Echinodermata Hemichordata Chordata Absent Present Mesodermal pouches Platyhelminthes 1 INTRODUCTION of kingdom Animalia m Classification helps in assigning a systematic position to newly described species. m What is the need to classify animals? m Characteristics of members – l l l Eukaryotic organisms Division of labour Definite growth pattern l l Multicellular and their cells lack cell wall Heterotrophic with holozoic mode of nutrition l Capable of locomotion l Sensory and neuromotor mechanism With some exceptions (Poriferans) m Notochord – Mesodermally derived rod like structure formed on the dorsal side during embryonic development in some animals m Animals without notochord – Non-chordates (Porifera to echinoderms) m Metameric Segmentation – Body is externally and internally divided into segments with a serial repetition of at least some organs m Animals with notochord – Chordates m rd About 2/3 of all species on earth are Arthropods (Most abundant are insects) Complex True coelomates Body cavity lined by mesoderm Organ system (Each system with a specific physiological function) ü ü ü û û û û û û û Acoelomates û (No body cavity) Ectoderm Mesoderm Coelom Endoderm Ectoderm Endoderm Mesoglea
2 Animal Kingdom: Non-Chordates NCERT Maps mSize Minute Large mWater flow Entry Exit mNumber Many Usually one mLocation Body surface Body surface Parameters Ostia Osculum m Water canal system Functions m Choanocytes/collar cells line the spongocoel (central cavity). Examples: m Name derived from cnidoblasts/ cnidocytes containg nematocysts, present on body and tentacles. Cylindrical Umbrella like Sessile Free swimming Polyp Medusa m Obelia exhibits 2 basic forms: Porifera (Sponges) Coelenterata (Cnidaria) Ctenophora (Sea walnuts) Platyhelminthes (Flatworms) Aschelminthes (Round worms) Habitat/Habit Exoskeleton Endoskeleton X Coral forms have skeleton of CaCO3 Parameters X X X Spicules/spongin fibres X X X X Digestive system/ Digestion m Digestive system absent m Intracellular digestion m Digestive system incomplete m Mouth on hypostome leading to body cavity Gastro-vascular cavity m Intra and extracellular digestion m Extracellular and intracellular digestion m Digestive system incomplete with single opening m Extracellular digestion m Some forms absorb food directly from body surface m Complete alimentary canal with muscular pharynx m Extracellular digestion Respiratory structure Cell surface Body wall Free living-body surface Free living-body surface Circulatory system Circulating fluid = water Excretory system/ Surface Excretory tube opens out through excretory pore Body surface Flame cells (Protonephridia) for excretion and osmoregulation Nervous system X Neurons appear + + + Asexual reproduction Fragmentation, gemmule formation Budding X High regeneration-Planaria capacity X Sexual reproduction Present Distinctly dioecious Fertilization Internal External Internal Development Indirect, larva morphologically distinct from adult Indirect/direct Indirect through many larval stages Indirect Indirect/direct (young one resembles adult) Unique features and examples Ctenoplana, m Exhibit Bioluminescence i.e., property to emit light m 8 external rows of comb plates for locomotion, hence, called comb jellies Examples: m st 1 ones with bilateral symmetry Examples: m Dorsoventrally flattened body m Hooks and suckers present in parasitic forms m st 1 ones with complete alimentary canal m Posterior end curved in males m Circular in cross-section m Females longer than male Examples: Wuchereria (Filaria worm), Ancylostoma (Hookworm) Mostly marine, some are fresh water (Spongilla) Food gathering Respiratory exchange Removal of wastes Sycon (Scypha) Euspongia (Bath sponge) Spongilla (Fresh water sponge) Mostly marine, some are fresh water (Hydra), sessile or free swimming Adamsia (Sea anemone) Aurelia (Jelly fish) Pleurobrachia Exclusively marine Free living or parasitic Taenia (Tapeworm) Fasciola (Liver fluke) Aquatic, terrestrial, parasitic in plants and animals 3 COMPARATIVE ACCOUNT FROM PORIFERA TO ASCHELMINTHES Examples: Physalia (Portuguese man-of-war), Pennatula (Sea-pen), Gorgonia (Sea-fan), Meandrina (Brain coral) Alternation of generation/ Metagenesis Asexually Sexually Male Female Ascaris (Round worm) m Present m Hermaphrodites Anchorage, Defense Capture of prey Functions ‘X’ indicates absence ‘+’ indicates presence m Present m Hermaphrodites m Present m Hermaphrodites
NCERT Maps Animal Kingdom: Non-Chordates 3 Annelida (Segmented worms) Arthropoda(Joint appendages) Largest Phylum Mollusca/Soft bodied Second Largest Phylum Echinodermata (Spiny skinned) Hemichordata (Half chordates) Parameters Body divisions/ appearance Distinct segments metameres/annuli Head, thorax, abdomen Head, muscular foot visceral hump Star like Proboscis, collar, trunk (worm like) Locomotory structure m Longitudinal and circular muscles m Parapodia/lateral appendages in some Joined appendages Muscular foot Water vascular system X Respiratory system/ surface Body surface Gills, book gills, tracheal system, book lungs Feather like gills in mantle cavity Water vascular system Gills Circulatory system Closed Open Excretory system Nephridia Malpighian tubules Gills X Proboscis gland Unique features and Examples Aquatic and Terrestrial Exclusively marine Exoskeleton X Chitinous/Cuticle Calcareous shells Spines X + Digestive system Mouth-lower side/ventral Anus-upper side/dorsal + Mouth with file like rasping organ, radula for feeding Nervous system Paired ganglia with double ventral nerve cord + + + Eyes (simple, compound), Antennae, Statocyst (balancing) Sense organs Eyes, Tentacles Tentacles + Mono/Dioecious Monoecious – Earthworm, Leech Dioecious – Nereis (aquatic form) Mostly dioecious Usually dioecious Dioecious Fertilization External/internal Usually internal External Usually external External Development Direct/Indirect Indirect Indirect with free swimming larva m st 1 ones with metameric segmentation and true coelom Examples: Pheretima (Earthworm) m Water vascular system that helps in Locomotion Capture and transport of food Respiration m Presence of rudimentary stomochord Saccoglossus Examples: m Earlier considered as subphylum under phylum Chordata but now placed as separate phylum under non-chordata Aplysia (Seahare) Pinctada (Pearl oyster), Examples: m Soft and spongy layer of skin forms a mantle over the visceral hump. Loligo (Squid), m Space between hump and mantle is mantle cavity. Sepia (Cuttlefish), Dentalium (Tusk shell), Chaetopleura (Chiton), Examples: + + COMPARATIVE ACCOUNT FROM ANNELIDA TO HEMICHORDATA l l All have complete alimentary canal with extracellular digestion All can reproduce sexually and are usually oviparous 4 Habitat Nereis Hirudinaria (Blood sucking leech) Indirect Pila (Apple snail) Octopus (Devil fish) Asterias (Star fish) Ophiura (Brittle star) Proboscis Collar Trunk Balanoglossus m Economically important insects- Apis (Honey bee), Bombyx (Silkworm), Laccifer (Lac insect) m Living fossil - (King crab) Limulus m Vectors - Anopheles,Culex, Aedes (Mosquitoes) m Gregarious pest - Locusta (Locust) Scorpion Prawn Butterfly Echinus (Sea urchin), Antedon (Sea lily) Examples: Cucumaria (Sea cucumber), m Presence of Calcareous ossicles
Animal Kingdom: Non-Chordates NCERT Maps 4 1. All of the following are basis of classification of animals except [NCERT Pg. 46] (1) Number of cells (2) Body symmetry (3) Nature of coelom (4) Arrangement of cells 2. Organ level of organisation is present in the members of which phylum?[NCERT Pg. 46] (1) Cnidaria (2) Ctenophora (3) Platyhelminthes (4) Porifera 3. What is true for open circulatory system? [NCERT Pg. 47] (1) Cells and tissues are directly bathed in blood (2) Capillaries are present (3) Blood is circulated only through a series of vessels of varying diameter (4) Present in earthworm 4. Digestive system in phylum Platyhelminthes [NCERT Pg. 47] (1) Has two openings to the outside of the body (2) Has one opening to the outside of the body (3) Is absent in most of the members (4) Opens through excretory pore to the outside of the body 5. When any longitudinal plane passing through the central axis of the body divides the organism into two identical halves, it is called [NCERT Pg. 47] (1) Bilateral symmetry (2) Radial symmetry (3) Asymmetry (4) Biradial symmetry 6. Choose the odd one w.r.t. coelenterates [NCERT Pg. 47] (1) Ectoderm (2) Endoderm (3) Mesoderm (4) Mesoglea 7. Triploblastic acoelomate animals belong to which phylum? [NCERT Pg. 48] (1) Ctenophora (2) Platyhelminthes (3) Aschelminthes (4) Annelida 8. Presence of truly coelomate animals ranges from phylum [NCERT Pg. 48] (1) Aschelminthes to Chordata (2) Annelida to Chordata (3) Platyhelminthes to Chordata (4) Ctenophora to Chordata 9. Metameric segmentation is present in [NCERT Pg. 52] (1) Pheretima (2) Ascaris (3) Balanoglossus (4) Pila 10. Which of the following is incorrect w.r.t. notochord? [NCERT Pg. 48] (1) Ectodermally derived (2) Rod-like structure (3) Present on the dorsal side (4) Absent in animals ranging from phylum Porifera to Echinodermata 11. Select the correct option w.r.t. sponges [NCERT Pg. 49] (1) All are marine (2) All are asymmetrical (3) Collar cells line spongocoel only (4) Usually monoecious 12. Choose the correct match w.r.t. excretory structure [NCERT Pg. 51-54] (1) Fasciola – Excretory tube (2) Ancylostoma – Flame cells (3) Laccifer – Malpighian tubules (4) Chaetopleura – Proboscis gland 13. Select the incorrect match w.r.t. fertilisation [NCERT Pg. 49-54] (1) Sponges – Internal (2) Ctenophores – External (3) Roundworms – Internal (4) Echinoderms – Internal