A technician keeps living mouse liver cells in a nutrient solution containing glucose. Air is bubbled through the solution continuously, so enough oxygen is available to the cells.
A carbon dioxide sensor measures the gas leaving the solution. The carbon dioxide concentration is higher than in gas leaving identical apparatus containing nutrient solution but no cells.
Which statement explains the sensor result and identifies how glucose was broken down?
Anaerobic respiration broke glucose down incompletely, forming lactic acid.
Aerobic respiration broke glucose down completely, forming carbon dioxide and water.
Aerobic respiration broke glucose down incompletely, forming lactic acid and carbon dioxide.
Fermentation broke glucose down incompletely, forming ethanol and carbon dioxide.
113 exam-style questions on OCR GCSE Biology 1.3 Respiration, covering 1.3.1 Cellular respiration supplies ATP, 1.3.2 Aerobic and anaerobic respiration, 1.3.3 Sugars and carbohydrates, 1.3.4 Amino acids and proteins, and 1.3.5 Fatty acids and lipids. Each one has a worked solution and a mark scheme showing where the marks go.