Sponges have specialized cells and an endoskeleton, but they lack tissues and body symmetry. ... They include jellyfish and corals, both of which have radial symmetry. All cnidarians have nematocysts, and many are bioluminescent. They may exist in medusa and/or polyp form.
Our elbow bends all the time, we bend it when we pick up things, when we eat, when we do mostly everything. Cows on the other hand dont pick up food with there feet, they use there mouths, and they probably only bend when they are walking.
He found a nuclear structure (cells) in plants by looking through a microscope
Answer: Providing shelter and spawning grounds to a wide range of ocean life, coral reefs serve an important role in the marine ecosystem. ... Another role is protection from strong ocean currents and high waves. As the name "barrier reef" implies, reefs act as a barrier protecting the shorelines.
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