Biodiversity of animals

• Advancements in order

  1. Porifera, sponges
  2. Cnidaria, jellyfish
  3. Plathelminthes, tapeworms
  4. Annelida, earthworms
  5. Arthropoda, crabs
  6. Chordata, rats
• Cephalisation 


  An accumulation of sense organs near the anterior part of the body
• All bilateral organims have cephalisation
• Ectoderm gives rise to outer covering of organism
• Mesoderm gives rise to to muscles
• Encoders gives rise to lining of digestive tract and organs like the liver and lungs
• Diploblastic animals have no body cavity and are made up of two tissue germ layers
• Triploblastic Organisms are all bilateral symmetrical and have three tissue germ layers