| A | B |
|---|
| food chain | shows the steps in which organisms get the food they need to survive |
| food web | shows how food chains in an ecosystem are related |
| vertebrate | an animal with a backbone |
| invertebrate | an animal without a backbone |
| symmetry | the way an animal's body parts match up around a point or central line |
| sponge | the simplest kind of invertebrate |
| sea urchin | has spherical symmetry |
| crayfish | they can be 0.8 to 16inches long |
