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Worms PowerPoint Presentation

Worms

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Worms

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  1. Worms 5th Grade

  2. 3 major Phyla • Flatworms • Roundworms • Segmented worms

  3. Characteristics of ALL worms • Invertebrates • Long, narrow bodies without legs • Have head and tail ends

  4. Do they have tissues, organs, and body systems? • Yes! Unlike sponges and cnidarians, worms DO have tissues and organs • Worms are the simplest organisms WITH A BRAIN

  5. How does a worm’s brain and sense organs work? • Sense organs can detect objects, food, mates, and predators quickly • Sense organs that are sensitive to light, touch, and vibrations pick up information from the environment • Braininterprets that information and directs the animal’s response

  6. Example: • A worm’s sense organ senses the vibrations of a footstep, and the brain tells the worm to quickly return to its underground burrow

  7. Reproduction • Worms have asexual and sexual reproduction depending on the species • Some worms reproduce asexually by breaking into pieces. • If you cut some kinds of worms into several pieces, a whole new worm will grow from each piece

  8. What kind of symmetry to worms have? • Bilateral Symmetry

  9. 1) Flatworms • Flat • soft like jelly • Ex. Tapeworms, Planarians, Flukes

  10. Flatworms CAN be parasites • Parasite: an organism that lives inside or on another organism • Parasites take food from their host • Host: the organism that the parasite feeds on

  11. Parasites: • Rob their hosts of food • Make the hosts weak • May injure the host’s tissues or organs • Rarely kill host • ALL flukes and tapeworms are parasites

  12. Fluke

  13. Flukes • 10,000 species of flukes • Range from .2 inches to 4 inches

  14. Tapeworm

  15. Tapeworms • Attack the intestines • Range from .04 inches to 50 ft

  16. Planarians • Free-living flatworms • Free-living organism: does not live in or on other organisms • Glide over rocks in ponds, slide over damp soil, swim slowly through the ocean

  17. Planarians are scavengers! • What is a scavenger?

  18. Scavengers: organisms that feed on dead or decaying material • Planarians feed like a vacuum cleaner • Glide onto their food and insert a feeding tube into it • Digestive juices flow out of the planarian and into the food, breaking down the food while it is still outside of the body • Planarian sucks up the partly digested bits

  19. Planarians are scavengers and predators Either feed on dead or decaying food Or Attack any animals smaller than they are

  20. Planarians

  21. Planarians • Size: usually between 1/8 of an inch to 1 inch • Some tropical forms can be up to 2 ft!

  22. Planarians • Have 2 dots that look like eyes • Eyespots: can detect light but cannot see a detailed image as human eyes can • Planarian head also has cells that pick up odors • Planarians rely mainly on smell, not light to locate food

  23. Planarians

  24. Tapeworm Life Cycle • http://www.youtube.com/watch?v=EEBbtwGqPEs