Animal Classification

4. one of a large group of animals with jointed appendages and an exoskeleton
6. an animal with a body temperature that is determined by its environment.
8. lack of mirror-image halves.
11. one of a group of animals with soft bodies and usually a shell
15. one of a group of animals with spiny skin.
17. a support structure one the outside of the animals body.
18. a mammal that provides its embryo with oxygen and food through a placenta

1. the effort to define the boundaries between the various created kinds of animals
2. an animal with a backbone
3. an animal that can regulate its internal body temperature
5. lives in water when young and on land as an adult
7. an animal that lacks a backbone
9. a mammal with a pouch in which to raise its young
10. a living internal support structure
12. the property of an object that means that it can be divided by one or more imaginary lines into mirror-image halves.
13. one of a group of animals with stinging cells, called cnidocytes.
14. one of a group of animals with no symmetry, cephalization or gut.
16. a flexible rod found in chordate animals