An individual's red blood cell (RBC) count and haemoglobin levels vary depending on their health and environment. The table below shows the average RBC count and haemoglobin concentration of a healthy adult and an adult suffering from iron-deficiency anaemia.
| Group | Average RBC Count (1012 cells/dm310^{12} \text{ cells/dm}^31012 cells/dm3) | Average Haemoglobin Concentration (g/dm3\text{g/dm}^3g/dm3) |
|---|---|---|
| Healthy Adult | 5.0 | 150 |
| Adult with Anaemia | 3.2 | 96 |
Calculate the percentage decrease in the average haemoglobin concentration of the adult with anaemia compared to the healthy adult.
Explain how a lower haemoglobin concentration causes the symptom of extreme tiredness.
44 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.