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Answer» The organisms belonging to the phylum Cnidaria exhibit the following characters. - They are primitive metazoans having tissue grade of organisation.
- They are aquatic both freshwater and marine, solitary or colonial with Radial symmetry.
- The body wall is diploblastic with outer ectroderm and inner endoderm. Ectoderm has specialised stinging cells called Nematocysts
- The body wall encloses a body cavity called coelenteron or Gastrovascular cavity.
- Coelenterates exist in two forms in their life cycle. The asexual reproducing form is called polyp and sexually reproducing form called Medusa. Thus they exhibit polymorphism.
- The polyp stage alternates with the medusa stage in coelectorates and is called Metagenesis.
- Respiratory, circulatory and excretory systern are absent.
- Reproduction occurs both by asexual and sexual methods. Asexual reproduction is by budding arid sexual reproduction is by production of Gametes.
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