1. Sometimes when we do heavy exercise, anaerobic respiration takes place in our muscle cells. What is produced during this process?

2. Yeast is used in wine and beer industries because it respires.

3. During the process of exhalation, the ribs move

4. Which are the gases involved in breathing?

5. Name the organ of the body in which the blood is oxygenated.

6. After heavy exercise, due to the accumulation of which substance we get muscle cramps ?

7. Yeasts are used in

8. In the following figure of respiratory system organs labelled by 1 and 2 are respectively:

9. Breathing rate in human beings in normal condition is