Science Life

4. An organ system that transports needed materials to cells and removes wastes.
6. A kind of symmetry in which any number of imaginary lines that all pass through a central point divide the animal into two mirror images
7. An animal with a backbone
9. An organ system that rids a body of wastes
11. An organ system that enables organisms to exchange gases with their surroundings
12. The maintenance of stable internal conditions
14. An invertebrate with a soft, unsegmented body protected by a hard outer shell
16. A marine invertebrate that has an internal skeleton and system of fluid filled tubes
17. An invertebrate that has an external skeleton, a segmented body, and jointed appendages.

1. An internal skeleton
2. A kind of symmetry in which a single imaginary line divides the body into left and right sides that are mirror images of each other
3. An organ system that has specialized structures for obtaining and digesting food
5. An animal without a backbone
8. external skeleton
10. A unicellular organism that lacks a nucleus and some other cell structures
13. An organism whose cells contain a nucleus
15. A radially symmetrical invertebrate that uses stinging cells to capture food and defend itself