Classification of living things (UNIT 8)

• Classification of living organisms

  1. Classification is systematic method to study living organisms by observing similar and different characteristics that can be recognized.
  2. Classification of living things allows the scientists to

  • compare similarities and differences of different species of organisms
  • locate the organisms easily
  • study and identify the organisms easily
• Animals can be divided into two main groups. These are the vertebrates and the invertebrates.
• Vertebrates

  • mammals
  • birds
  • amphibians
  • reptiles
  • fish
• Invertebrates

  • with joined legs and without joined legs

  Invertebrates with joined legs have segmented bodies and hard exoskeletons as well. They are called arthropods which include insects, spiders, crustaceans, scorpions, millipedes and centipedes.
• Mammals

  • Warm-blooded
  • Have hair or fur
  • Most give birth to live young (except platypus which lay eggs)
  • Breathe with their lungs
  • Feed their young with mother's milk

  e.g.

  • Humans
  • Bats
  • Whales
  • Dolphins
  • Platypus
• Birds


  • Warm-blooded
  • Have feather
  • Have breaks and wings
  • Breathe with their lungs
  • Lay eggs with hard shells

  e.g.

  • Penguins
  • Ducks
  • Sparrows
  • Ostriches
  • Owls
• Amphibians

  • Cold-blooded
  • Have moist skin
  • Young breathe through gills
  • Adults breathe through lungs on land and through their skin water
  • Lay eggs in water

  e.g.

  • Salamanders
  • Toads
  • Frogs
  • Newt
• Reptiles

  • Cold-blooded
  • Have dry, scaly skin
  • Breathe through lungs
  • Lay eggs with leathery shells on land

  e.g.

  • Crocodiles
  • Turtles
  • Snakes
  • Tortoises
• Fish

  • Cold-blooded
  • Have hard and slimy scales
  • Breathe through gills
  • Lay eggs
  • Have fins and tails to help them swim

  e.g.

  • Sharks
  • Sea horses
  • Clownfish
  • Salmon
  • Stingrays
• Invertebrates with joined legs

  • Three pairs of legs

  e.g. Ants, Files

  • Four pairs of legs

  e.g. Spider, Ticks

  • More than four pairs of legs

  e.g. Lobster, Shrimps, Crab, Millipedes
• Invertebrates without joined legs

  Worm-like

  • Non-segmented bodies - Roundworm, Pinworm
  • Segmented bodies - Leech, Earthworm

  Not worm-like

  • Tiny stinging threads - Jellyfish, Coral
  • Spiny skins and bodies - Starfish, Sea cucumber
  • Soft bodies with hard shells - Snail, Octopus
• Flowering plants


  • Vascular plants as they have true roots, stems and leaves
  • Reproduce by seeds which are found in fruits
• Non-flowering plants


  Mosses

  • Non-vascular plants as they do not have true roots, stems and leaves
  • Spores in capsule

  Ferns

  • Vascular plants as they have true roots, stems and leaves
  • Spores on underside of the leaves

  Conifers

  • Vascular plants as they have true roots, stems and leaves
  • Have needle-like leaves
  • Reproduce by seeds which are found in cones