Earthworm Laboratory Analysis Questions
1. Write the life process for which each structure listed below is used. (Movement, support,
respiration, feeding & digestion, internal transport, response, reproduction, excretion)
Anus __________________
Intestine _____________________
Aortic arches ________________
Setae ___________________
Blood ________________
Mouth ______________________
Blood vessels ____________________
Nephridia ___________________
Brain _____________________
Pharynx ____________________
Muscles __________________
Ovary _______________
Clitellum ___________________
Crop _____________________
Skin _____________________
Esophagus ____________________
Gizzard ___________________
Nerve cord __________________
2. What structures were seen in the earthworm that were not seen in any other animals studied
thus far?
3. Explain why the earthworm has so many more internal structures than the other animals
studied thus far. Support your answer in terms of any of the following: symmetry, body plan,
presence of a coelom, segmentation, & levels of organization.
4. How does the earthworm take in oxygen? With this method of respiration, what kind of
environment must the worm live in? Why?
5. The presence of what structures tells us that earthworms are hermaphroditic?
6.
The earthworm has a closed circulatory system. Explain what this means, and what
evidence you saw of this in your worm.
7. How can you tell the anterior from the posterior end of the earthworm?
8. How can you tell the ventral from the dorsal side of the earthworm?
9.
Why don’t the earthworms have any sense organs on the outside of their bodies as did the
planarians? Why don’t they need them?
10. Would the earthworm be described as having cephalization? Why or why not?
11. What evidence did you see (both internally and externally) that earthworms are segmented?
12. Earthworms can re-grow a posterior section of the body if cut in half, but cannot re-grow an
anterior section. Explain why this is so based on the structures seen in each part of your worm.
Is this re-growth considered asexual reproduction? Why or why not?