Unit 4: Continuity and Change
Topic 4.5: Gene Expression (HL) Questions
Practice 20 exam-style questions for IB Biology Topic 4.5. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
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Define the term transcription factor.
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Which change is an epigenetic change rather than a mutation?
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State the two processes that, together, make up the expression of a gene.
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State what is meant by the term epigenetics.
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State the stage of gene expression at which transcription factors act to control whether a gene is expressed.
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Define the term epigenetic change.
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What does it mean to say that a gene is 'expressed'?
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Expression of a gene is often measured from the amount of mRNA it produces.
State the relationship between the amount of mRNA from a gene and how strongly that gene is expressed.
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A change to a cell switches a gene off but leaves the DNA base sequence exactly as it was.
What kind of change is this?
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Which statement best describes an epigenetic change?
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What kind of molecule is a transcription factor?
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State what is meant by an epigenetic mark.
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At which stage is gene expression mainly controlled in a eukaryotic cell?
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Which list contains only environmental factors known to alter epigenetic marks?
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Which change to a gene is normally reversible?
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A mutation can change a protein's structure, but an epigenetic change does not.
Why?
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A gene produces 60 units of mRNA in liver cells and 4 units of mRNA in skin cells.
Both cell types contain the gene.
What is the best conclusion?
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In terms of gene expression, what best describes cell differentiation?
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How does tightly packed (condensed) DNA around histones affect a gene in that region?
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Methyl (CH₃) groups are added to the promoter of a gene.
What is the most likely effect on that gene?
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