vertebrates

• animals that have a vertebral column or backbone are called vertebrates
• all vertebrates have an internal skeleton made of bones or cartilage
• five main groups:

  • fish
  • amphibians
  • reptiles
  • birds
  • mammals
• fish:

  • streamlines
  • have fins for swimming
  • eyes
  • lateral line for detecting pressure changes in water
  • breathe dissolved oxygen from water using gills
  • skin is covered with scales
• amphibians:

  • smooth, moist skin
  • most live on land but return to water to breed
  • external fertilisation
  • external development
• reptiles:

  • dry scaly skin to cut down water loss
  • do not return to water to breed
  • internal fertilisation
  • external development
  • lay eggs with leathery, waterproof shells which stop them from drying out
• birds:

  • feathers
  • wings
  • no teeth, have beaks adapted to deal with different types of food
  • fertilisation is internal and development is external
  • lay eggs
  • homeothermic
• mammals:

  • hair or fur
  • internal fertilisation
  • internal development
  • homeothermic -> maintains constant internal temperature