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

What are their part in the body features' evolution?

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