1. INVERTEBRATES = NO BACKBONE!

2. Symmetry Definition- Similar in size, shape, and position Three types of symmetry 1. Spherical 2. Radial 3. Bilateral

3. Spherical Symmetry Spherical Symmetry: Everything is the same in all directions (as if on the surface of a sphere). The pollen of the hollyhock exhibits spherical symmetry (magnification x 100,000)

4. Radial Symmetry

5. Bilateral Symmetry

6. Sections of the Body Anterior = Front

7. Posterior = Tail

8. Dorsal = Top/Back

9. Ventral = Underside or Belly

10. Worms Phylum: PLATY Helminthes – flatworms Planaria- Free living organism (NOT a parasite!) CAN regenerate Hermaphroditic- Have both male and female reproductive structures Class: Trematoda- flukes-parasites

11. Worms:Unique Life Cycles Sheep Liver Fluke (Herma) 1. Found in the liver as an adult 2. Releases eggs in waste 3. Eggs become larvae 4. Enter a snail 5. Forms cysts 6. Cysts on the grass are eaten by animal!

12. Sheep Liver Fluke

13. Worms: Unique Life Cycles Cestoda (Herma) 1. Tape worms enter the body as cysts 2. Attach to intestines 3. Grow head called Scolex 4. Develop body sections called PROGLOTTIDS

14. Cestoda

15. Worms: Unique Life Cycles Nematoda – Round worms 1. Enters in food and water 2. Eggs become larvae 3. Burrows hole in intestines 4. Grows and produces 200,000 eggs per day! 5. Example:Ascaris

16. Ascaris

17. FUN FACT!!! 1/3 of world is infected with round worms!!

18. Worms: Unique Life Cycles Hookworms 1. Eggs and larvae are in warm, moist, damp soil 2. Enters human body through the bottom of the foot 3. Enters blood stream and travels to intestines. 4. Grows and develops eggs passed out in waste

21. Worms: Unique Life Cycles Heartworms 1. Found in dogs 2. Animal feces attach to heart vessels

23. Worms: Unique Life Cycles Trichina Worm (Trichinosis) 1. Forms cysts in muscle of pigs and hogs (pork) 2. Most enter in foods and water

24. Trichina Worm

25. Annelids-Segmented Worms Earthworms, Red worms- (Night crawlers) Bilaterally symmetrical, segmented worms Well developed Cephalization Closed circulatory system Hermaphroditic (Non-Parasites) Parasites- Leeches- Blood Suckers