A burns patient has lost a large area of skin and requires a skin graft. Doctors suggest using embryonic stem cells to grow replacement skin tissue for the patient. Explain why embryonic stem cells could be used to produce skin cells, and outline ONE ethical issue associated with using embryonic stem cells in this way.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Embryonic stem cells are obtained from very early human embryos. Scientists can culture these cells in the laboratory under specific conditions to direct their differentiation into a chosen cell type.
Model answer (5 marks)
Embryonic stem cells are undifferentiated and therefore have the potential to become any cell type. When cultured under the right conditions they can be directed to differentiate into specialised skin cells, providing the required tissue for a graft.
However, obtaining these cells requires the destruction of a human embryo, which raises ethical concerns. Some people believe the embryo is a human life and therefore object to its destruction for research or therapeutic purposes.
However, obtaining these cells requires the destruction of a human embryo, which raises ethical concerns. Some people believe the embryo is a human life and therefore object to its destruction for research or therapeutic purposes.
Examiner tips
- Use the terms "undifferentiated" and "totipotent" or "pluripotent" to show understanding of potency. Show the link between differentiation and specialised skin cells. State the ethical issue clearly and give a brief explanation of why it is contentious.
Common mistakes
- Using the word "multipotent" instead of totipotent/pluripotent. Failing to mention the destruction of the embryo. Giving an unrelated ethical issue such as cost or accessibility.
Mark scheme (5 marks)
- Embryonic stem cells are unspecialised / undifferentiated
- Embryonic stem cells can differentiate into any cell type (are totipotent / have the potential to become any cell)
- Cell differentiation allows the embryonic stem cells to become specialised skin cells
- Correct ethical issue identified — e.g. the embryo is destroyed in the process of obtaining the stem cells
- Ethical issue is developed — e.g. some people consider the embryo to be a human life / have moral or religious objections to destroying an embryo
Key terms in this question
Related
- All Edexcel A-Level Biology A: Salters-Nuffield (9BN0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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