Photo AI
The graph shows the heart rate of a fit person and of an unfit person at rest, during exercise and after exercise. - Edexcel - GCSE Biology - Question 3 - 2014 - Paper 1
Question 3
The graph shows the heart rate of a fit person and of an unfit person at rest, during exercise and after exercise.
Worked Solution & Example Answer:The graph shows the heart rate of a fit person and of an unfit person at rest, during exercise and after exercise. - Edexcel - GCSE Biology - Question 3 - 2014 - Paper 1
Step 1
A comparison to include three of the following: For the unfit person
Answer
- The unfit person's heart rate is higher during exercise compared to the fit person's.
- Both individuals reach their peak heart rates at similar times, but the unfit person's heart rate increases more quickly towards the maximum.
- The heart rate of the unfit person takes longer to decrease back to resting levels compared to the fit person after exercise.
Step 2
Calculate the heart rate for the unfit person during exercise: Correct substitution
Answer
Using the heart rate shown on the graph, the unfit person's heart rate during exercise is calculated as follows:
However, a mistake has been made in the interpretation here; likely the unfit person reaches around 140 bpm.
Step 3
An explanation that includes: the fit person recovers faster / has a shorter recovery period
Answer
- The fit person has a greater vital capacity and stroke volume, leading to more effective blood circulation and oxygen transport.
- The fit person undergoes less anaerobic respiration during exercise, resulting in reduced lactic acid accumulation.
- After exercising, the fit person experiences an EPOC (Excess Post-exercise Oxygen Consumption) that aids recovery and allows for more oxygen debt to be repaid quickly.