Worms 2BIbDF09 10/11

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