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==What are the three main classes of worms ?== | ==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 : | 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 | - flatworms or Platyhelminthes : | ||
- Segmented Worms or Annelida | - Tapeworms | ||
- roundworms or Nematoda | |||
- Segmented Worms or Annelida : | |||
- Earthworms | |||
- Polychaetes | |||
- Leeches | |||
==What are the main characteristics of each one?== | ==What are the main characteristics of each one?== | ||
==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 10 janvier 2011 à 12:06
What is a worm ?
Worms are invertebrate animals. They are multicellular with true tissues and bilateral symmetry and 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. There are several Phyla and each one live in a specific environment. Some of them are parasitic organisms that can live in a body or just live in soil or in the sea.
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 :
- Tapeworms
- roundworms or Nematoda
- Segmented Worms or Annelida :
- Earthworms - Polychaetes - Leeches