A respirometer shows that an organism takes in oxygen but produces no measurable carbon dioxide. Which conclusion is best supported by the information?
Aerobic respiration may be occurring, but the carbon dioxide may be absorbed or retained
Anaerobic respiration must be occurring because carbon dioxide is never produced aerobically
Fermentation must be occurring because oxygen is a product of respiration in yeast cells
Respiration has stopped because every energy transfer releases measurable carbon dioxide
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.