Cnidarians (Hydra View)

Card Set Information

Cnidarians (Hydra View)
2013-02-01 09:37:27
BIO 220

Ch Nutrition
Show Answers:

  1. Hydra type of digestion?
    extra and intracellu
  2. __ with __
    - __


    __= extracellular digestion
    __= intracellular digestion
    • flagella with cnidocytes
    • nematocyst
    • gastrovascular cavity
    • gastrodermal cells
  3. Explain hydra's body.
    • one opening in body called the mouth
    • Surrounding the mouth are tentacles, which function to help capture the prey and bring it to the mouth and then into the gastrovascular cavity 
  4. What does hte mouth lead to?
    gastrovascular cavity, which extends down length of organism
  5. Explain cell body.
    simple: only two layers thick with the inner layer of cells lining the gastrovascular cavity= gastrodermis
  6. Explain the prey's route.
    • The prey gets inside the gastrovascular cavityà gastrodermal cells release digestive enzymes into the cavity where some extracellular digestion will take placeà break down into smaller partsà gastrodermal cells through phagocytosis complete digestion intracellularly
    • it can exocytose nutrients to the epidermis
  7. Layers of the hydra.
    • Inner layer exposed to gastrovascular cavity; no need for complex transport of nutrients
    • Epidermal cells accept the nucleus, not the gastrodermal cells; the GC break down the material
  8. How the Tentacles Work in Capturing the Prey
    • 1) The tentacles have on them, cells called cnidocytes, which help in capturing the prey. How?
    •     a) composed of trigger that when something hits it, the trigger will release a coiled thread from inside the cell
  9. That coiled thread is part of a structure called the __, either stings the prey or wraps around the prey and capture and bring it mouth 

  10. Cnidocyte also plays a role in capturing__
     by having a nematocyst which can grasp the food and bring it to the mouth
  11. Nematocyst
    internal structure with thread attached
  12. Cnidocyte:
    structure with the nematocyst and trigger