A sports scientist used the apparatus in Fig. 1 to compare pulse rate before and after a 10 minute rowing test. A light sensor was clipped to the student's ...
Question 1 Report
A sports scientist used the apparatus in Fig. 1 to compare pulse rate before and after a 10 minute rowing test. A light sensor was clipped to the student's finger. Each pulse of blood through an artery changed the amount of light reaching the sensor. The computer displayed a pulse trace. Before exercise the student was sitting quietly. Immediately after rowing, the trace peaks were closer together. The student breathed more deeply after the test because active muscle cells needed more oxygen and produced more carbon dioxide.
(a) Name the measurement recorded by the sensor. [1]
(b) Describe the change in pulse rate after rowing. [1]
(c) Suggest why the heart rate increases during the rowing test. [2]
Answer Details
(a) The sensor records pulse rate, which reflects heart rate. [1]
(b) The pulse rate increases after rowing because the peaks are closer together in the trace. [1]
(c) Working muscle cells need more oxygen and glucose for respiration. Increasing heart rate makes circulation faster, so these materials are supplied more rapidly and carbon dioxide is removed more rapidly. [2]
Download The App On Google Playstore
Everything you need to excel in your exams
