Anatomy of an Earthworm
Name:______________________
External anatomy of the Earthworm
Internal Anatomy of the Earthworm
Dissection Questions:
1. Describe the shape of the dorsal (top) and ventral (bottom) surfaces of the earthworm’s body.
2. How many segments are on your earthworm? ____________
3. In which segment is the clitellum located? _______________ What is the function of the
clitellum?
4. Where are the setae located on the earthworm? _________________________
5. How many setae are on each segment?______________
6. Use your probe and softly poke the crop and gizzard. How do the walls compare?
7. Describe the contents found in the digestive tract. What does it look like?
Analysis and Conclusion Questions:
8. Why is it important to not make a deep cut with the scissors when dissecting your earthworm
specimen?
9. What do you think the function is of the typhlosole (in humans it is known as the villi) in worms?
10. How does the earthworm’s digestive system adapt it to filtering food out of the soil?
11. Describe two ways in which an earthworm’s body is adapted to life in the soil.
Critical Thinking:
12. What is the advantage for a worm to have a digestive tract like the one it has (straight line), instead
of the human digestive tract, which is more sac-like with a slower rate of passage?
13. Describe one way in which an earthworm is poorly adapted to life on land.
14. How might an earthworm’s lack of appendages be an adaptation to burrowing?
15. How much food do you think a worm eats each day?