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==Where do they live?== | ==Where do they live?== | ||
==What are their part in the body features' evolution?== | ==What are their part in the body features' evolution?== | ||
Version du 6 décembre 2010 à 12:26
What is a worm ?
Worms are invertebrate animals. They are multicellular with true tissues and bilateral symmetry [they have a soft and flexible body. They are protostomes] They probably appeared at the beginning of cambrian era and they are an important step of animals' evolution.
What are the three main classes of worms ?
There are separate in three classes that depending on their body shape, there are three main classes of worms : - flatworms or Platyhelminthes - roundworms or Nematoda - Segmented Worms or Annelida