Animal Kingdom Class 11 Notes Biology Chapter 4 - CBSE

Chapter : 4

What Are Animal Kingdom ?

Classification Of Animals

(On the basis of Organisation, Symmetry, Coelom development)

  • Kingdom
  • Level of Organisation
  • Symmetry
  • Body Cavity or Coelom
  • Phylum

Animals (Multicellular)

  • Cellular level
    • Mostly Asymmetrical
      • Acoelomata
        • Porifera
  • Tissue/Organ/ Organ system
    • Radial
      • Acoelomata
        • Coelenterata (Cnidaria)
        • Ctenophora
    • Bilateral
      • Without body cavity
        (acoelomates)
        • Platyhelminthes
      • With false coelom
        (pseudocoelomates)
        • Aschelminthes
      • With true coelom
        (coelomates)
        • Annelida
        • Arthropoda
        • Mollusca
        • Echinodermata
        • Hemichordate
        • Chordata

Classification Of Animals

Vertebrates (With Backbone)

  • Warm-blooded
    • Bird
    • Mammals
  • Cold-blooded
    • Fish
    • Reptiles
    • Amphibians

Invertebrates (Without Backbone)

  • Porifera
  • Platyhelminthes
  • Cnidaria
  • Arthopoda
    • Crustacea
    • Arachnida
    • Insects
    • Myriapoda
  • Annelida
  • Echinodermata
  • Mollusca

Salient Features of Different Phyla in the Animal Kingdom

Phylum Level of Organisation Symmetry Coelom Segmentation Digestive System Circulatory System Respiratory System
Porifera Cellular Various Absent Absent Absent Absent Absent
Coelenterata (Cnidarta) Tissue Radial Absent Absent Incomplete Absent Absent
Platyhelminthes Organ and Organ System Bilateral Absent Absent Incomplete Absent Absent
Aschelminthes Organ System Bilateral Pseudocoelomate Absent Complete Absent Absent
Annelida Organ System Bilateral Coelomate Present Complete Present Absent
Arthopoda Organ System Bilateral Coelomate Present Complete Present Present
Mollusca Organ System Bilateral Coelomate Absent Complete Present Present
Echinodermata Organ System Radial Coelomate Absent Complete Present Present
Hemichordata Organ System Bilateral Coelomate Absent Complete Present Present
Chordata Organ System Bilateral Coelomate Present Complete Present Present

Phylum Chordata

  • Subphyla
    • Urochordata (or) Tunicata
      E.g., Ascida
      • Protochordata
  • Cephalochordate
    • Eg. Branchinostoma
      • Protochordata
  • Exclusively marine
  • In Urochordates, notochord present only in larval tail
  • In cephalochordates, it is present from head to tail and persists life long.

Vertebrata

  • Possess notochord only in embryonic stages.
  • Notochord replaced by cartilaginous or bony vertebral column.
  • Have ventral heart with 2, 3, or 4 chambers, kidneys for excretion,
  • Have paired appendages (fins or limbs).