Practice IB Biology Topic D2.2 Gene Expression with authentic exam-style questions for both SL and HL students. This question bank focuses on the exact syllabus content for D2.2 Gene Expression and mirrors Paper 1A, 1B, 2 style where relevant.
Get instant solutions, detailed explanations, and build confidence with questions aligned to IB examiner expectations.
The function of silencer DNA sequences is to:
Epigenetic mechanisms can regulate gene expression in development, physiology and responses to the environment.
Outline the consequences of genomic imprinting in lion–tiger hybrids, explaining the origin of size differences between ligers and tigons.
Describe how environmental pollutants, such as air pollution, can influence the epigenetic regulation of immune response genes.
Explain the mechanism by which oestrogen regulates gene expression related to endometrial development and maintenance in the uterine cycle.
In the image below, the left panel shows changes in global DNA methylation levels (%) in somatic cells over three generations ( to ) following an environmental stimulus in the generation. The right panel displays the expression level of a phenotypic trait over six generations ( to ), highlighting how the phenotype changes across generations despite no changes in the DNA sequence.
State the trend in global DNA methylation (%) from to .
Identify the generation in which the phenotypic trait expression peaks. Suggest a possible epigenetic explanation for why expression peaks at that generation.
Explain how DNA methylation can be involved in the heritable silencing of gene expression.
Describe how epigenetic changes, such as those shown here, can contribute to phenotypic plasticity without altering the DNA sequence.
Figure showing transcriptional regulation of gene in a eukaryotic cell.
State the function of the promoter shown in the figure.
Explain the role of (i) transcription factors and (ii) mediator proteins in this diagram.
Describe how the enhancer and its associated proteins regulate the transcription of gene .
Suggest one reason why this regulatory mechanism allows differential gene expression in different cell types.
Which of the following sequences acts to increase transcription when bound by an activator?