Community Q&A
A-Level Biology May/June 2025 Q5(c): One desirable feature of artificial blood products, such as artificial red blood cells,…
A-Level Biology · Paper 9700/22 · May/June 2025 · Question 5(c) · [3 marks]
One desirable feature of artificial blood products, such as artificial red blood cells, is that they should be economical to produce. Suggest other desirable features of artificial blood products.
A full-marks model answer with a mark-by-mark examiner breakdown is below.
1 answer
- accepted ✓
- The product should not stimulate an immune response in the recipient. This ensures it is not rejected by the body and avoids allergic reactions.
- It must be sterile and free from pathogens. This eliminates the risk of transmitting infections, which is a concern with donated blood.
- It should have a long shelf life and be easy to store. This makes it more practical for use in emergencies and remote locations compared to donated blood which requires refrigeration and expires quickly.
How the marks are awarded
- B1 — The first point correctly states that the product should not stimulate an immune or allergic response, matching mark scheme point 2.
- B1 — The second point correctly identifies that the product should be free from pathogens, eliminating the risk of infection, as per mark scheme point 3.
- B1 — The third point suggests a long shelf life and ease of storage, which is a valid practical feature listed in mark scheme point 4.
Common mistakes
- Repeating the point given in the question, for example, stating 'it should be cheap to make'.
- Giving answers that are too vague, such as 'it must be safe' without specifying how (e.g., non-toxic, no immune response).
- Stating that it must not carry pathogens but then failing to provide any other distinct points for the remaining marks.
- Confusing the properties of artificial blood with real blood, for example, suggesting it should contain platelets or white blood cells, when the question specifies artificial red blood cells.
Examiner tip: For 'suggest' questions, think about the ideal characteristics of a product from different perspectives, such as safety, practicality, and biological function, to generate a range of distinct points.
AI-generated model answer, grounded in the official Cambridge mark scheme and reviewed by the MarkScheme team. Mark your own answer to this question →
Your answer
Sign in to answer this question.