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

To label…. Mouth All questions page 159 Tentacles Body Basal disc Bud All questions page 159 All questions page 161