Two athletes complete the same sprint. Athlete X consumes more oxygen during recovery than athlete Y. Assuming both began under the same conditions, which inference is best supported?
Athlete X necessarily completed more aerobic respiration and produced no lactic acid
Athlete X necessarily had a lower breathing rate throughout the sprint than athlete Y
Athlete X necessarily converted all glucose into ethanol rather than lactic acid
Athlete X probably accumulated more lactic acid that required removal after exercise
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.