27-2 Roundworms

Kingdom Animalia - Phylum Nematoda

Unsegmented worms
Pseudocoelom ("false coelom")
- body cavity contains organs

Digestive tract with 2 openings, mouth & anus

Free-living - predators
Parasites - humans and animals

Reproduction: Sexual reproduction,
Separate sexes (male & female)

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

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

Ascarid Worms (common roundworm)
- lives in intestine
- eggs are passed out in the feces


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

Research on C. elegans

- first organism to have DNA completely sequenced