click below
click below
Normal Size Small Size show me how
Chapter 12 Vocab
| Term | Definition |
|---|---|
| bird | an endothermic vertebrate that has feathers and a four-chambered heart; lay eggs. |
| contour feather | one of the large feathers that give shape to a bird's body. |
| down feathers | short, fluffy feathers that are specialized to trap heat and keep the bird warm. |
| crop | an internal storage tank for storing food inside the body after swallowing it. |
| gizzard | a thick-walled muscular part of the stomach that squeezes and grinds the partially digested food. |
| lift | an upward force that causes the bird to rise. |
| mammal | endothermic vertebrates that have a four-chambered heart and skin covered with fur or hair. |
| mammary glands | organs that produce milk inside the mother's body. |
| diaphragm | a large muscle that is located at the bottom of the ribs. |
| monotreme | egg-laying mammals. |
| marsupial | mammals whose young are born at an early stage of development and they usually continue to develop in a pouch on their mother's body. |
| gestation period | the length of time between fertilization and birth. |
| placental mammal | develops inside its mother's body until its body systems can function independently. |
| placenta | an organ in pregnant female mammals that passes materials between the mother and the developing embryo. |