A kayaker increases the intensity of paddling. Scientists estimate the oxygen needed by the arm muscles for aerobic respiration and the maximum oxygen delivered to these muscles by the blood.
| Time in seconds | Oxygen needed by the muscles in dm³ per minute | Maximum oxygen delivered in dm³ per minute |
|---|---|---|
| 60 | 2.2 | 2.4 |
| 90 | 3.1 | 2.6 |
Using the data for both 60 seconds and 90 seconds, explain the change in respiration in some of the kayaker's arm muscle cells and why the pathway used at 90 seconds gives a smaller yield of ATP per molecule of glucose.
92 exam-style questions on AQA GCSE Biology 4.2 Respiration, covering 4.2.1 Aerobic and anaerobic respiration, 4.2.2 Response to exercise, and 4.2.3 Metabolism. Each one has a worked solution and a mark scheme showing where the marks go.