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Figures 5 and 6 show the percentages of oxygen, carbon dioxide and nitrogen in the air inhaled and exhaled by a long distance runner while training - Edexcel - GCSE Physical Education - Question 6 - 2018 - Paper 1
Question 6
Figures 5 and 6 show the percentages of oxygen, carbon dioxide and nitrogen in the air inhaled and exhaled by a long distance runner while training. (a) Analyse, us... show full transcript
Worked Solution & Example Answer:Figures 5 and 6 show the percentages of oxygen, carbon dioxide and nitrogen in the air inhaled and exhaled by a long distance runner while training - Edexcel - GCSE Physical Education - Question 6 - 2018 - Paper 1
Step 1
Analyse, using the data in Figures 5 and 6, the difference between the runner’s inhaled and exhaled air.
Answer
The comparison of the inhaled and exhaled air shows distinct differences in the composition of gases.
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Oxygen Levels: The runner inhales air containing approximately 21% oxygen, while the exhaled air contains only about 16% oxygen. This indicates that the runner uses up some of the oxygen during their physical exertion.
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Carbon Dioxide Levels: The inhaled air contains a minimal amount of carbon dioxide (0.04%), but in contrast, the exhaled air has a significantly higher concentration of approximately 4%. This suggests that the runner's body produces more carbon dioxide as a byproduct of metabolism during exercise.
Step 2
Step 3
Explain two reasons why Figure 8 represents the runner’s breathing during exercise.
Answer
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Increased Breathing Rate: In Figure 8, the graphs show that the runner's breathing rate increases, which is evident from the closer spacing of the waves. This indicates a higher frequency of breathing, which is typical during exercise due to increased oxygen demands.
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Increased Depth of Breathing: Figure 8 also illustrates that the depth of each breath (tidal volume) appears to become deeper, evident from the greater amplitude of the waves, increasing from 0.5 to 2.0 dm³. This suggests that during exercise, the runner takes in more air with each breath to meet the metabolic demands of their body.