| A | B |
|---|
| Cold-blooded | an animal whose body temperature changes with its surroundings |
| Cartilage | a soft, bonelike material that bends |
| Gills | thin fethery structures that are filled with blood and used for breathing by some animals that live in water |
| Fin | a structure on a fish that helps it move through water |
| Scale | a flat, bony structure that covers and helps protect the bodies of some animals |
| Fish | vertebrates that live in water |
| Amphibian | a cold-blooded vertebrate that lives part of its life in water and part on land |
| Lungs | organs through which animals get oxygen from air |
| Tadpoles | the fish like stage in the life of a frog |
| Reptile | a cold-blooded vertebrate that has lungs and dry skin |
| Warm-blooded | an animal whose body temperature stays the same |
| Birds | a warm-blooded vertebrate |
| Down | small, fluffy feathers near a bird's body that trap air and help to keep the bird warm |
| Molting | to shed an outer covering |
| Mammals | a warm-blooded vertebrate that is usually covered with fur or hair and whose young are fed from the female's milk glands |
