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Animals similar to flatworms that have a complete digestive system and round bodies.

Atoms Practice
Practice Roundworms
Practice Now
Ring Around The Roundworm
Teacher Contributed

Ring Around The Roundworm

Crosssections of male and female roundworms (Acaris sp.). Note the size difference!

Student Exploration

That's a Worm

When people hear the word "worm", they don't usually think of roundworms. The reason is simple, people hardly ever see roundworms. Free-living forms are small, and the parasitic ones people commonly interact with are endoparasitic, meaning they live inside other organisms. But just because people don't think about roundworms or see them doesn't mean we aren't affected by them. Watch this video to see how these unseen creatures can affect your health.


Now that you've learned about how roundworms can affect your health, let's take a look at the worms themselves. https://www.youtube.com/watch?v=a7RAoJ_2W5g

Extension Investigation

Use the resources below to answer the following questions"

  1. How does the species of roundworm affect the symptoms of infection? What is the most commons means of infection?
  2. What are some of the symptoms of roundworm infection? How variable are they? What are some of the methods used to diagnose roundworm infection?
  3. Why are roundworms a good example of sexual dimorphism? Why is the female larger with these organisms? Can you think of any advantage a male would have from being larger?
  4. What do male roundworms use their hook for? Where does this process take place?
  5. What do some roundworms do when they are ingested by an inappropriate host? Why is this an effective strategy for them?

Resources Cited

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