4. Complete Activity 6.4 (Page 62). Take a deep breath. Measure the size of the chest with a measuring tape (Fig. 6.6) and record your observations in Table 6.2. Measure the size of the chest again when expanded and indicate which classmate shows the maximum expansion of the chest.
Answer:
The Activity 6.4 should be carried out along with your classmates in the following way:
Aim: To know how much your and your classmates’ chests expand during breathing and indicate which classmate shows the maximum expansion of the chest.
Materials Required: Measuring tape.
Procedure: Refer to the figure below:
(i) Take a deep breath and hold your breath. Now take a measuring tape and wrap it around your chest or have a classmate do it for you. Record the measurement in cm.
(ii) Then exhale completely and similarly measure your chest in this position. Note down this measurement in cm.
Observation:
You will notice that the measurements indicate that everyone’s chest expanded on inhaling and contracted on exhaling. The range of expansion for all the classmates was between 2 – 4 cm. The maximum expansion of the chest was recorded for Ramesh and was = 4 cm.
Table 6.2: Effect of breathing on the chest size of some classmates
| Name of the classmate | Size of the chest (cm) | ||
| During inhalation | During exhalation | Difference in size | |
| Ramesh | 74 | 70 | 4 |
| Riya | 69 | 66.5 | 2.5 |
| Sachin | 73 | 70 | 3 |
| Anisa | 67 | 65 | 2 |
| Self | 72 | 69 | 3 |
Conclusion:
When you inhale the ribs move up and outwards and the diaphragm moves down, thereby expanding the chest cavity. When you exhale the ribs move down and inwards and the diaphragm moves upwards and this causes contraction of the chest cavity. So, the measurement of the chest after inhaling will be higher than after exhaling.
“Complete Activity 6.4 (Page 62). Take a deep breath. Measure the size of the chest with a measuring tape (Fig. 6.6) and record your observations in Table 6.2. Measure the size of the chest again when expanded and indicate which classmate shows the maximum expansion of the chest.” – Solved.
Related Links:
Solution to Extended Learning Question 1
Solution to Extended Learning Question 2
Solution to Extended Learning Question 3
Solution to Activity 6.1
Solution to Activity 6.2
Solution to Activity 6.3
Solution to Activity 6.5
Solution to Activity 6.6
Solution to Chapter 6 Respiration in Organisms
