Explain why embryonic stem cells are considered more useful than adult stem cells for treating a wide range of diseases and injuries.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Scientists are researching ways to use stem cells to repair damaged tissues and organs. Two sources of stem cells are embryonic stem cells and adult stem cells, such as those found in bone marrow.
Model answer (5 marks)
Embryonic stem cells are totipotent/pluripotent and can differentiate into any cell type, whereas adult stem cells are multipotent and can only become a limited range of specialised cells. Because of this, embryonic stem cells can be used to repair a wider variety of tissues and treat more diseases. They are found in very early embryos and are unspecialised, having not yet undergone differentiation. However, their use raises ethical concerns as it requires the destruction of an embryo, which some consider a potential human life.
Examiner tips
- Use the terms totipotent/pluripotent and multipotent to show understanding of potency.
- Explain the practical advantage (wider range of tissues) before mentioning the ethical issue.
- Keep the answer concise and directly linked to the marks given.
- Mention the ethical concern only once, as it is a single point in the scheme.
Common mistakes
- Confusing totipotent with pluripotent or vice versa.
- Failing to state that adult stem cells are multipotent and limited in differentiation.
- Over‑explaining the ethical issue or repeating it unnecessarily.
Mark scheme (5 marks)
- Embryonic stem cells can differentiate into any cell type (totipotent/pluripotent)
- Adult stem cells can only differentiate into a limited range of cell types
- Therefore embryonic stem cells could be used to treat a greater variety of diseases / repair more tissue types
- Embryonic stem cells are found in very early embryos and are unspecialised (have not yet undergone cell differentiation)
- There is an ethical concern about using embryonic stem cells because it requires the destruction of an embryo, which some consider a potential human life
Key terms in this question
embryonic stem cells · adult stem cells
Related
- All Pearson Edexcel A-Level Biology A (9BI0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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