Doctors compared three treatments for one type of cancer.
The Table shows the results.
Table
| Treatment | Percentage of cancer cells killed | Percentage of healthy cells near the tumour that were damaged |
|---|---|---|
| chemotherapy drug | 70 | 40 |
| radiotherapy | 65 | 30 |
| drug attached to a monoclonal antibody | 72 | 5 |
Calculate the percentage decrease in the damage to healthy cells when the drug attached to a monoclonal antibody is used instead of the chemotherapy drug.
Explain why the drug attached to a monoclonal antibody damages fewer healthy cells than chemotherapy or radiotherapy.
Suggest one reason why this monoclonal antibody treatment cannot be used to treat every type of cancer.
45 exam-style questions on Edexcel GCSE Biology 5.3 Immune system and medicines, covering 5.3.1 The specific immune system, 5.3.2 Response to immunisation, 5.3.3 Advantages and disadvantages of immunisation, 5.3.4 Antibiotics and bacterial infections, 5.3.5 Aseptic techniques in culturing, 5.3.6 Cross-sectional areas of cultures, 5.3.7 Stages of developing new medicines, and 5.3.8 Production of monoclonal antibodies. Each one has a worked solution and a mark scheme showing where the marks go.