1. Bird An endothermic vertebrate that has feathers, a four chambered heart and lays eggs Contour Feather A large feather that helps give shape to a bird’s body Down Feather A short fluffy feather that traps heat and keeps a bird warm Crop A bird’s internal storage pouch that allows it to store food inside its body after swallowing it Gizzard A muscular thick walled part of the bird’s stomach that squeezes and grinds partially digested food

2. Lift The difference in pressure between the upper and lower surfaces of a bird’s wing that allows a bird to fly Mammal An endothermic vertebrate with a four chambered heart, skin covered with fur or hair, young feed from milk produced by the female. Mammary Gland The organ in female mammals that produces milk for the mammal’s young Diaphragm A large muscle located at the bottom of a mammal’s rib cage that functions in breathing Monotreme A mammal that lays eggs

3. Marsupial A mammal’s whose young are born alive but mature inside of the female’s pouch Gestation Period The length of time between fertilization and birth of a mammal Placental Mammal A mammal that develops inside its mother’s body until its body systems can function independently Placenta A membrane that becomes the link between the developing embryo and the mother Zoology The study of animals