2. drawing air into and out of the lungs for gaseous exchange

3. breathing air out of the lungs

4. the process by which organisms exchange gases with their environment

5. breathing air into the lungs

6. muscles in between each pair of ribs, responsible for moving the rib cage up and down when they contract

7. the process of breathing in smoke from cigarettes being smoked by a nearby smoker

8. the volume of air remains in the lungs after the deepest exhalation

9. a group of sticky, oily substances in cigarette smoke which stimulates mucus secretion in the respiratory tract

10. a space inside the thorax of the mammalian body in which the lungs are located

11. the volume of air breathed in or out of the lungs during quiet breathing

12. the movement of air to and from the respiratory surface

13. the maximum volume of air that can be exhaled after the deepest inhalation

Marks =