Heart activity can be tracked in several ways. Fig. 3.1 presents two ECG traces: one was taken while the person was resting and the other while they were exercising. In the ECG trace recorded at rest, Fig. 3.1 marks the time taken for one heart beat.
(a(i))[2]
Estimate the person's resting heart rate from the ECG trace in Fig. 3.1.
(a(ii))[4]
Explain why the ECG trace taken during exercise is different from the ECG trace taken at rest.
(a(iii))[1]
Suggest one other way of monitoring the activity of the heart.
(b(i))[2]
Complete the sentence. An oxygen debt results in a build-up of [BLANK] in the [BLANK] during vigorous exercise.
(b(ii))[4]
Outline how the body clears an oxygen debt.
Worked solution & mark scheme
This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Either \((17 \times 0.04)s = 0.68 s\), or \(2.8 \div 4 = 0.7 s\), or \(4 \div 2.8 = 1.43\) beats per s” …