What are the progressive structural features of annelids? How do oligochaetes differ from polychints?

| March 2, 2021 | education

1) What are the progressive structural features of annelids? 2) How do oligochaetes differ from polychints? 3) What adaptations do leeches have in connection with a parasitic lifestyle? 4) What is the importance of annelids in ecosystems?

1) Structural features of annelids are as follows:
* The body is divided into segments.
* Have a secondary body cavity – the whole.
* Closed circulatory system.
* Sense organs – on the head segments.

2) The difference is the presence of parapodia in polychaetal worms – special outgrowths.

3) Adaptations are as follows: 1. An extensive digestive system. 2. Two suction cups. 3. Anticoagulant properties of saliva.

4) Ringworms are of such importance in the ecosystem: food for animals, loosen the soil, are important in medicine.



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