Cell differentiation produces specialized structures and functions by regulating gene expression, so cells with essentially the same genome develop distinct proteomes and phenotypes.
Coverage 2023–2023 · Updated 15 Jul 2026
Cell differentiation produces specialized cell types mainly by changing which genes are expressed, not by giving each cell a completely different genome.
Signals and transcription factors open or silence particular genes. The resulting proteins alter structure and function, so cells with the same DNA can become neurons, muscle cells or secretory cells.
Trace the causal chain:
A muscle precursor expresses contractile-protein genes, while a neuron expresses ion-channel and neurotransmitter genes; both retain the same genome.
Different cell types are not usually created by losing unrelated genes; selective expression is the key mechanism.
This objective is assessed through structured response, commonly using Identify / Determine / Outline.
Identify / Determine / Outline
Build the answer around this relationship: Differentiated cells usually retain the same genome.
Explaining differentiation by claiming that specialized cells contain different sets of genes.
Representative question
Outline the reasons for differences between the proteomes of cells within a multicellular organism.
The HL extension asks how complex cell organization could arise and become useful. Endosymbiosis explains the origin of mitochondria and chloroplasts using bacterial evidence. Differentiation explains how cells with the same genome become specialized through different gene expression and proteomes. Multicellularity explains why adhesion, communication, and differentiation allowed larger bodies and division of labour.
