| A | B |
|---|
| Vertebrate | An animal that has a backbone |
| Endotherm | An animal that can use body heat from chemical reactions in the body's cells to maintain a constant body temperature |
| Ectotherm | An organism that needs sources of heat outside of itself. |
| Lateral Line | A faint line visible on both sides of a fish's body and marks that location of sense organs that detect vibrations in the water. |
| Gill | A respiratory organ in which oxygen from the water is exchanged with carbon dioxide from the blood. |
| Swim Bladder | A gas-filled sac that is used to control buoyancy; also known as a gas bladder. |
| Lung | A respiratory organ in which oxygen from teh air is exchanged with carbon dioxide from the blood. |
| Tadpole | The aquatic, fish-shaped larva of a frog or toad. |
| Metamorphosis | a phase in the life cycle of many animals during which a rapid change from teh immature form of an organism to the adult form takes place. |
| Amniotic Egg | A type of egg that is surrounded by a membrane, the amnion, and that in reptiles, birds, and egg-laying mammals contains a large amount of yolk and is surrounded by a shell. |
| Preening | In birds, the act of grooming and maintainging their feathers |
| Molting | The shedding of an exoskeleton, skin, feathers, or hair to be replaced by new parts |
| Down Feather | A soft feather that covers the body of young birds and provides insulation to adult birds |
| Contour Feather | One of the most esternal feathers that cover a bird and that help determine its shape. |
| Lift | an upward force on an object that moves in a fluid |
| Brooding | To sit on and cover eggs to keep them warm until they hatch; to incubate. |
| Mammary Gland | In a female mammal, a glad that secretes milk. |
| Diaphragm | A dome-shaped muscle that is attached to the lower ribs and that functions as the main muscle in respiration. |
| Placental Mammal | A mammal that nourishes its unborn offspring through a placenta inside its uterus. |
| Gestation Period | In mammals, the length of time between fertilization and birth. |
