A research team grew replacement skin from stem cells for patients with severe burns. All the patients had antigens P and Q on their body cells.
The table shows the outcomes of the transplants.
| Stem-cell source | Antigens on the replacement skin | Number of patients | Number whose transplant was rejected |
|---|---|---|---|
| Patient's own body | P and Q | 100 | 2 |
| Unrelated donors | P and Q | 100 | 4 |
| Unrelated donors | R and S | 100 | 61 |
A student concludes, 'Replacement skin must be grown from the patient's own stem cells to have a low risk of rejection.'
Use the data and your knowledge of the immune system to explain whether this conclusion is correct.
181 exam-style questions on OCR GCSE Biology 6.3 Monitoring and maintaining health, covering 6.3.1 Health and disease, 6.3.2 Interactions between diseases, 6.3.3 Spread of communicable diseases, 6.3.4 Common infections and diseases, 6.3.5 Physical plant defence responses, 6.3.6 Chemical plant defence responses, 6.3.7 Detecting and identifying plant diseases, 6.3.8 White blood cells and platelets, 6.3.9 Non-specific defence systems, 6.3.10 The immune system, 6.3.11 Monoclonal antibodies, 6.3.12 Vaccines and medicines, 6.3.13 Aseptic techniques, 6.3.14 Discovery and development of new medicines, 6.3.15 Causes of non-communicable diseases, 6.3.16 Treatments for cardiovascular disease, 6.3.17 Lifestyle factors and non-communicable diseases, 6.3.18 Cancer, 6.3.19 Stem cells in medicine, 6.3.20 Gene technology in medicine, and 6.3.21 The human genome and medicine. Each one has a worked solution and a mark scheme showing where the marks go.