1. WARM UP Compare and contrast flatworms and roundworms, based on their clades.

2. Roundworms Phylum Nematoda

3. General Characteristics 12,000 species – Most are tiny – C. elegans Live in nearly all habitats – Lots in soil – Most free-living, some parasites

4. Structure Round body with 2 openings (mouth and anus) – Complete tube digestive system False coelom – “Empty” space around gut

5. Structure 3 tissue layers – Ectoderm Epidermis w/ cuticle – Endoderm Digestive tube – Mesoderm Nervous and excretory systems

6. Reproduction Dioecious – Separate sexes Eggs in one, sperm in the other Dimorphism – Female larger than male

7. Parasite Diversity Ascaris – Intestinal Heartworms – Dogs – Enter through mosquito bites Hookworms – Soil – Burrow through feet

8. Parasite Diversity Trichinella spiralis – Intestinal – Trichinosis Wucheria bancrofti – Lymph nodes – Elephantiasis – Transmitted through mosquitoes

9. Parasite Diversity Guinea worm – From contaminated water – Escapes out of skin Pinworms – Intestinal – Lay eggs outside body

10. WRAP UP List 3 different ways to contract a roundworm parasite. List 6 different ways to prevent the contraction of a roundworm parasite.