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Figure 13 shows the heart rate of person A and person B - Edexcel - GCSE Biology - Question 8 - 2020 - Paper 1
Question 8
Figure 13 shows the heart rate of person A and person B. Person A does not do any regular exercise. Person B has been running regularly for one year. Both peopl... show full transcript
Worked Solution & Example Answer:Figure 13 shows the heart rate of person A and person B - Edexcel - GCSE Biology - Question 8 - 2020 - Paper 1
Step 1
Compare the heart rates of person A with the heart rates of person B.
Answer
During the exercise, the heart rate of person A is higher than that of person B.
This could be attributed to person A's lack of regular exercise, which means their heart needs to work harder to meet increased demands during high intensity exercise.
Additionally, while person A's heart rate increases more dramatically than person B's during exercise, person B's heart rate remains relatively stable at a lower level due to their developed cardiovascular fitness.
Step 2
Calculate the cardiac output for person B before exercising.
Answer
To calculate cardiac output, we use the formula:
Given:
- Stroke Volume for person B = 61 ml/beat = 0.061 liters/beat.
- Heart Rate before exercise (assumed resting heart rate) = 70 beats per minute (typical average).
Calculating:
So, the cardiac output for person B before exercising is 4.27 litres per minute.
Step 3
Explain why the heart rate for person A needed to be higher than the heart rate for person B during exercise.
Answer
The heart rate for person A needed to be higher than that of person B during exercise due to their lower fitness level.
Person A, not being accustomed to regular exercise, requires a faster heart rate to supply muscles with adequate oxygen and nutrients during intense physical activity.
In contrast, person B, who has developed a greater efficiency in their cardiovascular system through regular training, can maintain a lower heart rate while still achieving similar physiological demands.