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=What is a worm ?= | =What is a worm ?= | ||
Worms are invertebrate animals. They are multicellular with true tissues and bilateral symmetry | Worms are invertebrate animals. They are multicellular with true tissues and bilateral symmetry and they have a soft and flexible body. | ||
They probably appeared at the beginning of cambrian era and they are an important step of animals' evolution. | [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 ?== | ==What are the three main classes of worms ?== | ||
Version du 10 janvier 2011 à 11:03
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 - roundworms or Nematoda - Segmented Worms or Annelida