1. ROUNDWORMS Kingdom Animalia - Phylum Nematoda
--Pseudocoelom ("false coelom") -- Digestive system has two openings with mouth and anus.

2. Interesting Facts About Nematodes
Prevalence: They are the most numerous of all multicellular animals.
Ecological Significance: They are found in nearly all parts of the earth and are an important part of food chains and soil health.
Parasite Success: ¼ of the world is infected with hookworm! (a roundworm intestinal parasite)

3. Similarities to Platyhelminthes
Bilateral Symmetry
What is bilateral Symmetry?
What might be one advantage?
Cephalization
What is cephalization?
What might be an advantage?

4. Roundworms & Disease
Trichinosis (trichinella worm) - cysts within the muscles are consumed (undercooked food) -- worm grows in intestine -- forms cysts in the muscles of the new host -- symptom: terrible pain in muscles

5. Filarial Worms - found in Tropical regions of Asia
-- usually transmitted by mosquitoes -- causes elephantiasis

6. Ascarid Worms (common roundworm) - lives in intestine - eggs are passed out in the feces
Most roundworms infect dogs, but occasionally they find their way into human hosts

7. Hookworms
- burrow into the skin from soil - mature in the intestines --hooks used to attach and suck blood

8. Research on C. elegans (MODEL ORGANISM)
first organism to have DNA completely sequenced
It is a very simple, free living roundworm
They have a fixed number of cells, which is very useful to learn about development. You can track the history of every cell in the body!