Question

Give an account on phylum Annelida.

Answer 1

1. These are bilaterally symmetrical, triploblastic, first true coelomate animals with an organ-system grade of organization.
2. Body is externally divided into segments called metameres joined by ring-like structures called annuli.
3. It is covered by a moist thin cuticle.
4. Setae and parapodia are locomotor organs.
5. Sexes may be separate or ünited (hermaphrodites).
   e.g- Nereis, Earthworm, Leech.