Muscle cells respire anaerobically during a 200 m sprint. Which statement explains why?
Oxygen is not needed by muscle cells that are contracting very quickly.
Glucose cannot be delivered to the muscles fast enough to meet the demand.
Glucose is completely oxidised only when the muscles contract very quickly.
Oxygen cannot be delivered to the muscles fast enough to meet the demand.
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.