After finishing a 400 m race, a runner continues to breathe deeply and quickly for several minutes.
Explain why the runner continues to breathe deeply and quickly after the race has finished.
Blood flowing through the runner's muscles carries lactic acid to the liver. Describe what happens to the lactic acid in the liver.
A trained athlete repays their oxygen debt more quickly than an untrained person. Suggest one reason.
51 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.