1 / 11

Worms

Worms. Flatworms. ectoderm. mesoderm. Bilateral symmetry Have organs & systems Primitive brain Pharynx: mouth tube 3 body layers Ectoderm Mesoderm Endoderm Gasses pass in/out by diffusion Reproduction: Asexual: stretch and break apart Sexual: “fencing”. Able to “regenerate”.

breanna-kramer
Download Presentation

Worms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Worms

  2. Flatworms ectoderm mesoderm • Bilateral symmetry • Have organs & systems • Primitive brain • Pharynx: mouth tube • 3 body layers • Ectoderm • Mesoderm • Endoderm • Gasses pass in/out by diffusion • Reproduction: • Asexual: stretch and break apart • Sexual: “fencing” Able to “regenerate” endoderm http://www.youtube.com/watch?v=0L_mJoG4nts

  3. Flatworms • Bilateral symmetry • Have organs & systems • Primitive brain • Pharynx: mouth tube • 3 body layers • Ectoderm • Mesoderm • Endoderm • Gasses pass in/out by diffusion • Reproduction: • Asexual: stretch and break apart • Sexual: “fencing”

  4. Flatworm Parasites • Tapeworms • Larvae enter through undercooked meat • Larvae grow • Scolex (head with hooks) attach to wall of intestines • Food absorbed through skin • Grow up to 12 meters • Eggs released in poop • Contaminated poop water consumed Larvae not killed in cooking process

  5. Roundworms (Nematodes) • Protostomes; Bilateral symmetry • Small in size (few mm) • Nerves control longitudinal muscles • What’s new? • Mouth and anus • Pseudocoelum: body cavity to aid with circulation & digestion • Separate male/female • Some free-living; Many parasites

  6. Roundworm Parasites • Hookworms • Larvae enter through bare feet walking in contaminated water • Migrate into lungs • Migrate into esophagus and swallowed into stomach • Larvae mature inside intestines • Mating occurs inside host • Eggs exit the host in poop https://www.youtube.com/watch?v=DxL2qHBetvI Egg

  7. Segmented Worms(Annelids) • What’s new? • Coelum: cavity to aid with circulation & digestions • Completely surrounded by muscle • Several organ systems • Complex digestive system • Circulatory sys: 2 blood vessels • Nervous sys: Primitive brain and nerve cord • Muscular sys: Circular & longitudinal muscles • Gas exchange through skin • Eat organic waste Longitudinal muscles Circular muscles

  8. Segmented Worm Reproduction M F . . . . . . • Hermaphroditic • Ventral surfaces press together • Mucus holds worms together • Sperm transferred to each • Sperm pouch forms • Sperm & eggs enter pouch as worm backs out • Baby worms develop inside pouch . F M

  9. Segmented Leeches • Live in calm, freshwater • Suckers attach to host • Release anaesthetic to hide presence • Can eat up to 10x own weight

  10. Segmented Leeches blood blood blood • Live in calm, freshwater • Suckers attach to host • Release anaesthetic to hide presence • Can eat up to 10x own weight • Medicinal use: • Help restore blood flow when body part is severed and reattached Ouch!

More Related