1. Flatworms and Roundworms: Not your typical earthworms!
Science 6
Study Pack #3

2. Today’s Goal…
I can compare flatworms and roundworms.

3. Flatworms
Invertebrates with long, flattened bodies and bilateral symmetry
Have 3 layers of tissues organized into organs and organ systems
Must search for food

4. Flatworms
Planarians
Free living – they don’t depend on an organism for food or a place to live
Have a digestive system with one opening

5. Flatworms
Tapeworms
Parasites – live in or on a “host” that provides them with food
Have hooks and suckers to attach to host
Can infect humans

6. Roundworms Example: heartworm disease
It’s body is a tube within a tube with a fluid-filled cavity in between the tubes
Their digestive tract has two openings
They can be predators, decomposers, or parasites