A scientist measures the relative concentrations of oxygen and carbon dioxide in the air in an alveolus and in blood entering the capillaries around it. The measurements are shown in the table.
| Condition | Oxygen concentration in alveolar air (relative units) | Oxygen concentration in blood entering capillaries (relative units) | Carbon dioxide concentration in alveolar air (relative units) | Carbon dioxide concentration in blood entering capillaries (relative units) |
|---|---|---|---|---|
| Normal ventilation | 100 | 30 | 5 | 50 |
| Reduced ventilation | 70 | 30 | 25 | 50 |
Explain how reduced ventilation affects the diffusion of oxygen and carbon dioxide between the alveolus and the blood.
304 exam-style questions on AQA GCSE Biology 2.2 Animal tissues, organs and organ systems, covering 2.2.1 The human digestive system, 2.2.2 The heart and blood vessels, 2.2.3 Blood, 2.2.4 Coronary heart disease: a non-communicable disease, 2.2.5 Health issues, 2.2.6 The effect of lifestyle on some non-communicable diseases, and 2.2.7 Cancer. Each one has a worked solution and a mark scheme showing where the marks go.