Bioniac

Phylum – Arthropoda • This is the largest phylum of Animalia which includes insects .  • Over two-thirds of all named species on earth are arthropods  •They have organ-system level of organisation. •They are bilaterally symmetrical , triploblastic , segmented and coelomate animals.  • The body of arthropods is covered by chitinous exoskeleton .  • The body consists of head, thorax and abdomen .  •They have jointed appendages ( arthros-joint , poda-appendages ). • Respiratory organs are gills , book gills , book lungs or tracheal system . • Circulatory system is of open type. • Sensory organs like antennae , eyes ( compound and simple ), statocysts or balancing organs are present. • Excretion takes place through malpighian tubules . • They are mostly dioecious .  • Fertilisation is usually internal . • They are mostly oviparous . • Development may be direct or indirect . Examples:  • Economically important insects – Apis (Honey bee), Bombyx (Silkworm), Laccifer (Lac insect

Phylum – Annelida • Latin , annulus : little ring • May be aquatic ( marine and fresh water ) or terrestrial ; free-living , and sometimes parasitic . •They exhibit organ-system level of body organisation and bilateral symmetry .  • T riploblastic , metamerically segmented   • coelomate . • Their body surface is distinctly marked out into segments or metameres  , which is why the phylum name is  Annelida   •They possess longitudinal and circular muscles which help in locomotion.  • Aquatic annelids like  Nereis possess lateral appendages ,  parapodia , which help in swimming.  • Circulatory system Closed .  • Nephridia (sing. nephridium ) help in osmoregulation and excretion. • Neural system consists of paired ganglia (sing. ganglion ) connected by lateral nerves to a double ventral nerve cord . • Nereis , an aquatic form, is dioecious , but earthworms and leeches are monoecious . • Sexual   Reproduction. Example: • Nereis •Pheretima (Earthworm) •

Phylum – Aschelminthes • Body is Circular   in cross-section. • Also called ROUNDWORM . • Free-living , aqatic , terrestrial , parasitic . •  Organ   level   of   body   organisation   is seen • Bilaterally   Symmetrical , Triploblastic , Pseudocoelomate . • Alimentary canal complete   with well developed Muscular   Pharynx . • Body waste is removed by an Excretory   Tube   through an Excretory   Pore . • DIOECIOUS   (Sex is seperate) • Oftern seen that Female are longer   than male • Internal   Fertilization • Development Direct / Indirect . Exmple: •   Ascaris (Roundworm) • Wuchereria   (Filaria worm) • Ancylostoma (Hookworm) Example of Aschelminthes: Ascaris

Phylum – Platyhelminthes • Dorso - ventrally   flattened   body structure(thats why it is called Flatworms ) • Mostly Endoparasitic • Bilaterally   symmetrical , Triploblastic , Acoelomate • Flatworms show Body - Level   of   Organisation . • In Parasitic form, Hooks   and Suckers   are present • Flame   Cells   help in Osmoregulation   and Excretion . • Hermaphrodite • Flatworm named Planeria   show high regenaration capacity. • Internal   fertilization. • Development through many larval stages. Example: •  Taenia (Tapeworm) •  Fasciola (Liver fluke)

Phylum - Ctenophora • Commonly known as Sea - walnut   or Comb - Jellies . • Ctenophores are exclusively  marine •  Radially   Symmetrical,   Diploblastic . • Ctenophores exhibit Tissue   level   of body organisation. • Their body possess eight    external rows of ciliated COMB   PLATE   (Hepls in Locomotion ) • Intracellular   and Extracellular   digestion seen. • Ctenophora phylum's well marked property is BIOLUMINESCENCE   (Living organism's light emitting feature) • Hermaphrodite   • Reproduction in only sexual   mode • External   fertilization with Indirect   development. Example: •  Pleurobrachia •  Ctenoplana

Phylum - Coelenterata(Cnideria) •  Aquatic,   Mostly   marine,   Sessile  or free swimming   • Radially   symmetrical animals • Cnideria name is derived from Cnidoblast   or Cnidocytes   •  Cnidoblast   cells   contain Stinging   capsule   or NEMATOCYST      Structure of Nematocyst cell • Cnidoblast   cells   are present on tentacles   and body and used for anchorage,   defense,   prey   capturing . • Cniderians have a central gastro-vascular   cavity   with a single opening. • Mouth in Cniderians is present of HYPOSTOME . • Extracellular  and Intracellular   digestion. • Some Cniderian live Coral   have a skeleton composed of  calcium carbonate   (CaCO3) • Two basic body form is shown named polyp   and medusa . • Polyp   stage is Sessile,   Cylindrical e.g. Hydra ,  Adamsia etc. • Medusa   stage is umbrella-shaped and free-swimming   e.g. Jelly Fish ( Aurelia ) • Cniderans may or may not posess both of the stages in their life cycle. If both forms are present in their

Phylum - Porifera • Commonly known as   sponges. • Generally marine ,  mostly  asymmetrical . • Multicellular, cellular level of organisation. • Primitive animals. • Water Transport System or Canal System  present. • Water enters the body cavity/central cavity through minute small pores named Ostia  and goes out through a big pore named Osculum   • Canal system helps the poriferans in food gathering,   respitory exchange,   waste removal   etc. • The central cavity is known as Spongocoel   which is lined by Choanocytes   or Collar   cells .  • Intracellular   digestion • Body of poriferans are supported by Spicules   or Spongin   fibres . • Hermaphrodite   (sex is not seperate) •  Asexual   reproduction  -   Fragmentation Sexual Reproduction  - Gamete   Formation   • Internal  fertilization • Indirect   development • Possess larval stage that is morphologically   distinct   from the adult stage Example: • Sycon (Scypha) • Spongilla (Fresh Water Sponge) • Eusp

Classification of Animal Kingdom: This diagram showa the classification of Kingdom Animalia on the basis of factors discussed before Click  here for part-1 Click  here for part-2 Click here  for part-3 Click  here for part-4 Click  here for part-5

Segmentation Some animals have body externally and internally divided into segments with serial repetation of atleast some organs as shown in earthworm, where body shows metameric segmentation. This is metamerism Notochord It is a mesodermally origined  rod-like structure on dorsal side of embryonic development in some animal . Animals who have this structure are called chordates and those who don't are called non-chordates

Coelom Def.- Coelom is a cavity present between body wall and gut wall. It is lined by mesoderm      In the basis of presence and type of coelom, animals are classified into 3 types 1) Acoelomates: The animals in which body cavity is absent os called acoelomate e.g. Platyhelminthes 2)Pseudocoelomates: In some animals, body cavity is not lined by mesoderm. Instead, the mesoderm is present as scattered pouches in between ectoderm and endoderm. Such body cavity is called pseudocoelom and such the animals possessing them is called pseudocoelomate e.g. Aschelminthes  3)Coelomate: Animals that possess a body cavity lined by mesoderm are known as coelomate e.g. Annelids to Chordates Types of animal on the basis of coelom structure a)Coelomate b)Pseudocoelomate c)Acoelomate

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Body Organisation Animals have three germinal layers of cell in their embryonic stage. Those layers are called Ectoderm , Endoderm and Meroderm . On the basis of presence of mesoderm or middle layer, animals are divided into two  categories- • Diploblastic: Animals that have only two embryonic layers are called diploblastic body organisation. They lac the mesoderm layer. An undifferentiated layer called mesoglea is present instead of mesoderm e.g. Coelenterates • Triploblastic: Animal that have all three embryonic layers are called to have triploblastic body organisation. Mesoderm is present in between Ectoderm and Endoderm. e.g. Platyhelminthes to Chordates   Body organisation (Germinal layers) (a) Diploblastic (b) Triploblastic Click  here  for part 1 of this chapter Click  here  for part 2 of this chapter

Symmetry • Asymmetrical: Any plane that passes through the center doesn't divide the following organism into two equal half e.g. sponges • Radial Symmetry: Any plane that passes through the central axis of the body divides the following organism into two equal halves e.g.   Coelenterates , Ctenophores, Adult Echinoderms      Radial Symmetry( Hydra sp. ) • Bilateral Symmetry: The body of the following organism can be divided into two equal halves if and only if the cutting plane pass through in a particular way through central axis e.g. Annelids , Arthropods etc. Bilateral Symmetry( Brachyura sp.) Click  Here  for part 1 of this chapter

Basis of Classification: Levels of Organisation *All members of Kingdom Animalia is multicellular •Cellular Level of Organisation:   1) Cells are arranged as loose aggregates   2) Some division of labour occur among the cells e.g. Sponges •Tissue Level of Organisation: 1) Cells performing the same function are arranged intotossues e.g. Coelenterates •Organ Level of Organisation: 1) Tissues are grouped together to form organs, each specialised for a particular function e.g. Platyhelminthes •Organ System Level of Organisation: 1) Organs have associated to form functional systems, each system concerned with specific physiological function  e.g. Annelids to Chordates Types in case of Organ System Level of Organisation: •Incomplete Digestive System:      Possess only one single opening outside the body which act as both mouth and anus e.g. Platyhelminthes •  Complete Digestive System:     Possess two openings • Open Type Circulatory System:    Blood is pumped out of heart and cells and tis