Edexcel A Level Biology A (Salters-Nuffield)
Edexcel A Level Biology A (Salters-Nuffield) Topic 3: Stem Cells and Gene Expression Exam Questions
Free Edexcel A Level Biology A (Salters-Nuffield) exam questions on Topic 3: Stem Cells and Gene Expression, with mark schemes. Covers totipotent and pluripotent stem cells, differentiation, gene expression, epigenetics and the use of stem cells.
Topic 3: Stem Cells and Gene Expression exam questions
These packs of real past exam questions cover the whole of Topic 3: Voice of the Genome, including Topic 3: Stem Cells and Gene Expression. Work through every question on this sub-topic, then mark your answers against the mark scheme.
StemUp mark scheme flashcards
Edexcel A Level Biology A (SNAB) 9BN0 Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
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About Edexcel A Level Biology A (Salters-Nuffield) Topic 3: Stem Cells and Gene Expression
This part of Topic 3 explains how one cell gives rise to many cell types. Expect questions on epigenetics and ethics of stem cell use.
What you need to know
- Stem cells Totipotent cells can form any cell type; pluripotent cells can form most. Sources include embryos and adult tissues.
- Differentiation Different genes are switched on and off, so cells make different proteins.
- Epigenetics DNA methylation and histone modification change gene expression without changing the base sequence.
- Phenotype Results from genotype and the environment; many traits are polygenic.
Common mistakes in Topic 3: Stem Cells and Gene Expression
- Saying differentiated cells lose genes.
- Confusing totipotent and pluripotent.
- Ignoring the role of the environment in phenotype.
Try three Topic 3: Stem Cells and Gene Expression exam-style questions
1. Explain how cells become specialised. (2 marks)
Show the mark scheme answer
Some genes are switched on and others off (1), so only certain proteins are made, giving the cell its structure and function (1).
2. Explain how DNA methylation affects gene expression. (2 marks)
Show the mark scheme answer
Methyl groups added to DNA (1) prevent transcription factors binding, switching the gene off (1).
3. Give one ethical concern about embryonic stem cell research. (1 mark)
Show the mark scheme answer
Embryos are destroyed when stem cells are taken.
Topic 3: Stem Cells and Gene Expression FAQs
What does this part of SNAB Topic 3 cover?
Stem cells, differentiation, gene expression and epigenetics.
What is a polygenic trait?
A characteristic controlled by many genes, often also affected by the environment.
Are induced pluripotent stem cells included?
Yes, as an alternative to embryonic stem cells.
Revise this topic with flashcards: Edexcel A Level Biology A (SNAB) 9BN0 Flashcards, with mark scheme answers for Anki and Quizlet.
