What are the “stinging cells” found mainly on tentacles in this phylum? What are the organelles contained within these cells that are released like a harpoon? Class can have 2 body forms: a cylindrical form known as a and/or a free floating, swimming form that (functions in sexual reproduction) is known as a .

Both body forms have a single opening into an incomplete digestive system known as the (GVC).

Having 2 layers cells (from ectoderm and endoderm only) is known as . Mesoderm is never developed in Cnidaria.

Hydra- What is the outside layer of cells called? and What is the inside layer of cells called? The noncellular layer between these 2 layers is called the . The bud represents what kind of reproduction? (sexual or a sexual)

Look up Obelia . Look for the feeding polyp (has tentacles) and the reproductive polyp. What are the “cookies” found in the reproductive polyp? What body form is necessary for sexual reproduction?

A sedentary (attached to a surface) lifestyle, also known as sessile. The 2 classes of Cnidaria with predominant sessile lifestyles are and .

The predominant kind of symmetry in Cnidarians is . This kind of symmetry is adapted to a sessile lifestyle or free floating lifestyle.

The sea anemone is included in class of Cnidaria. Pictured on page 4 is the rose bubble tipped anemone in the hall tank. The picture of the clownfish (in our classroom) with the sea anemone represents mutualism, a kind of symbiotic relationship where both organisms benefit.