1.5 invertebrate animals

• Vertebrates


  Animals with a backbone as part of a bony skeleton
• Invertebrates


  Animals without a backbone
• Arthropod classes


  • Insects
  • Arachnids
  • Crustaceans
  • Myriapods
• Arthropods


  • Most numerous of all animals, both in terms of number of different species and number of individuals in any one species
• Insectsthat are arthropods

  • Show an interesting adaptation in their life cycle called metamorphosis that allows them to use the resources of their habitat to the maximum
• Metamorphosis


  Change of body form that allows different stages which do not compete for the same food sources and can be highly specialised for different functions
• All animals have one common characteristic - they feed on organic molecules
• Features common to arthropod classes

  • Jointed limbs
  • Hardened exoskeleton
  • Mouthparts
• insects

  • 3 body section
  • 3 pairs of legs
  • 2 pairs of wings
  • Compound eyes
• Insects are the most abundant of all animals on land
• Complete metamorphosis is an adaptation that helps explain why there are so many insect species
• Insects have three main parts of their central nervous system: brain, subesophageal ganglion, and thoracic ganglia.
• Spiders

  2 body sections

  4 pairs of legs

  no wings