| A | B |
|---|
| Contour feathers | oneof the most external feathers that cover a bird and help determine its shape and color |
| gestation period | In mammals the length of time between fertilization and birth |
| brooding | to sit on and covrr eggs to keep them warm until they hatch |
| diaphragm | a dome shaped muscle attached to the lower ribs an allows the lungs to fill with air |
| monotreme | a mammal that lays eggs |
| down feather | soft feathers that cover the body of young birds and provide insulation to adult birds |
| marsupial | mammals that carry their young in a pouch |
| tadpole | the aquatic, fish shaped larva of a frog or toad |
| lungs | respiratory organs in which oxygen from the air is exchanged with carbon ioxide from the blood |
| swim bladder | a gas filled sac that is used to control buoyancy in bony fish |
| ectotherm | an organism that needs sources of heat outside of itself; cold blooded |
| lateral line | a faint line visible on both sides of a fish body that allows the fish to detect vibrations in the water |
| gills | An organ in fish that remove oxygen from the water |
| vertebrate | An animal that has a backbone |
| notochord | a still flexible rod that runs down the dorsal side of the body - becomes the backbone |
| Chordata | A phyla of vertebrate animals |
| nerve cord | a structure that runs along the back and develops into the spinal cord |
| pharyngeal pouches | structures that develop into gills or other body parts |
| cartilage | a tough material that makes up the ears and nose and is found in joints |
| external fertilization | fertilization of the egg outside the female body |
| internal fertilization | fertilization of the egg inside the body of the female |
| evolution | a change of species over time |
| closed circulatory system | a system where the blood is contained in vessels |
| endoskeleton | a skeleton that is located inside the body made of bone or cartilage |
| metamorphosis | a phase in the life cycle of amphibians during which a rapid change from the immature form of an organism to the adult form takes place |
| ecological indicator | a way that amphibians can be early signs of changes in an ecosystem |
| amnniotic egg | the egg of a reptile or bird that is protected by a shell |
