Biology 210
Lab Questions: Phylum Annelida
You will learn the answers to most of these questions in class and in lab.
Great resource: http://www.bumblebee.org/invertebrates/ANNELIDA.htm
1. What does the word annelida mean?
2. Recall, some of the nematode worms appeared superficially to have external rings. Describe true segmentation in annelids. How is the true segmentation in annelids differ from having rings around the ectoderm as in nematodes?
3. What two layers of muscles exist in annelids?
Which muscle layer, present in platyhelminthes, is absent in annelids?
4. Earthworms (class oligochaeta) and marine polychaete worms (class polychaeta) have bristles (“chaetes”) protruding from their body segments, while leeches (class hirudinea) lack these bristles. What is the function of these bristles (chaetes)?
5. Annelids have the following type of coelom condition ____________ a. acoelous b. pseudocoelous c. schizocoelous eucoelous d. enterocoelous eucoelous Which other phyla have this type of coelom?
6. Are annelids covered with cuticle or with chitin? How does cuticle differ from chitin? Can annelids molt?
7. When an annelid grows with age, it increases its number of its segments. Which end (anterior or posterior) of the worm has the most recently formed segments?
8. Describe the annelid’s digestive system [list the structures and their appearance, location and function].
9. Describe the annelid’s circulatory system. Is it open or closed? How many hearts does an earthworm have? Where are they located? Describe the path blood takes through the worm’s body.
10. Describe the annelid’s respiratory (gas exchange) system. Does it have lungs? Gills? How does it accomplish gas exchange? Why do annelids have to live in moist habitats?
11. Describe the excretory system of the annelid. How is this different from what other worm phyla have possessed?
12. Describe the function and