Question

Question 11
On an average, an adult human being at rest breathes 15–18 times per minute. The breathing rate, however, may differ under different conditions. Arrange the following activities given in the box in order of increasing breathing rates and give reason for your answer.

sleeping, cycling, brisk walk, watching TV

Answer 1

Respiratory rates:

1. The respiratory rate at rest is 15-18 breathes per minutes, which is why when the person is resting on it a posture of rest, they have the same respiratory rate.
   
2. Here sleeping is the most rested position while watching TV just requires a little more ​number of breathes.
   
3. Respiratory rate increases while performing intense physical exercise.
   
4. Brisk walk requires walking at a high speed causing intense physical exercise that has a higher breathing rate.
   
5. However, cycling requires the activity of more muscles compared to brisk walking and hence requires more respiratory rate to provide the requirement of excess oxygen than rest.
   

Final Answer: Ascending order of processes: sleeping > watching T.V. > brisk walk > cycling.