| A | B |
|---|
| Compared with the limbs of most amphibians, the limbs of reptiles tend to be | located farther beneath the body |
| All reptiles reproduce by | internal fertilization, and most are oviparous |
| Which of the following is NOT a characteristic of all birds? | They can fly. |
| An endotherm is an animal that | can generate its own body heat |
| What is the order in which food passes through the digestive system of a seed-eating bird? | crop-stomach-small intestine-large intestine |
| In which part of a bird's digestive system is food stored and moistened before it enters the stomach? | crop |
| The main function of contour feathers is to | provide the lifting force and balance needed for flight |
| A bird's respiratory system is more efficient than that of other land vertebrates because | air flows through the lungs in only one direction |
| The structure of a bird's heart ensures that | oxygen-rich blood never mixes with oxygen-rich air |
| The largest order of birds consists of | perching birds |
