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Hydra. Lesson 17 Notes. I. Basics. Freshwater organism Multicellular Tubular. Hydra Swimming. http:// www.youtube.com / watch?feature = player_detailpage&v =9MEt0Ot7Pkc. II. Structures. 6 tentacles around mouth Basal disc opposite mouth used to attach to surfaces/organisms 2 layers
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Hydra Lesson 17 Notes
I. Basics • Freshwater organism • Multicellular • Tubular
Hydra Swimming http://www.youtube.com/watch?feature=player_detailpage&v=9MEt0Ot7Pkc
II. Structures • 6 tentacles around mouth • Basal disc opposite mouth used to attach to surfaces/organisms • 2 layers • Inner – gastrodermis • Outer – epidermis • Mesoglea – jelly-like substance between inner and outer layers
IV. Reproduction • Warm weather: budding (asexual) • Cold weather (fall): sexually; drop eggs which hatch in the water • Dioecious: production of male or female parts
Hydra Budding http://www.dnatube.com/video/11330/Reproduction-Of-Hydra
III. Feeding • Nematocysts: stinging structures on tentacles • Release poisonous toxin • Tentacles draw food into mouth • Digestive enzymes in tube break down food in liquid • Nutrients taken in by diffusion • Wastes leave via mouth
Hydra catches Daphnia http://www.youtube.com/watch?feature=player_detailpage&v=Kukv0AtIVdU
Hydra eating Sea Monkey http://www.dnatube.com/video/1440/Hydra-and-sea-monkey-1