1. Flatworms

2. Phlylum Platyhelminthese = Flatworms

3. Flatworm FIRSTs!! Bilateral symmetry
Directional motion = 1st mobile predator
Cephalization – development of a head
Ganglia: bundle of nerve cells make up a pre-brain
Nerves concentrated at ‘head end’ since sensory cells were concentrated at that end
Sensory nerves formed bundles = ganglion
Eyespots detect light
Auricles detect chemicals ‘smell’
2 nerve cords transmit info to rest of body
Flatworm FIRSTs!!

4. New Innovations in Excretory System
cellular waste still removed by diffusion
Protonephridia (NEW)
flame cells help regulate solute concentration
Evolve in to the nephrons of mammal kidneys
First Kidney

5. Flatworm Reproduction
1st internal fertilization
Evolutionary advantage
Make fewer gametes
Save energy
Hermaphrodites = make both eggs & sperm
Evolutionary advantage = can mate with any other member of your species that you can find!

6. Asexual reproduction by fission

7. Ancestral Traits Gastrovascular cavity for digestion & circulation
Mouth in center of body
Respiration (gas exchange) by diffusion

8. Free-living Flatworms = Class
Marine
Fresh-water

9. Classes of Flatworm 1) Free living example = Planaria 2) Flukes
parasites in blood & liver
swimmers itch
3) Tapeworms

10. Flukes = Class
Parasites of blood and liver

11. Swimmer’s Itch =Schistosoma

12. Tape Worms = Class

13. Human Tape Worm Sources =Under cooked Prevention Beef (N. America)
Pork(S. America)
Fish (Asia)
Prevention
Cook your meat!!!
Wash your hands after using the restroom
Don’t drink contaminated water