Question

How do cells become specialized?
• Mitosis creates genetically unique cells that can do different tas
• Mitosis creates specialized cells for different purposes.
• Genetically identical cells undergo differentiation to alter gene e
Genetically identical cells undergo differentiation to make them

Answer 1

Best answer: Genetically identical cells undergo differentiation to alter gene expression to make them specialized.

Why:
- Mitosis usually produces genetically identical daughter cells (not genetically unique).
- Specialization (differentiation) happens after mitosis when cells turn on and off different sets of genes so they make different proteins and take on different shapes and functions.

Key mechanisms that drive specialization:
- Differential gene expression (different transcription factors active in different cells).
- Epigenetic changes (DNA methylation, histone modification) that stably change which genes are expressed.
- Cell signaling and morphogen gradients (Notch, Wnt, Hedgehog, growth factors) from neighboring cells or the environment.
- Asymmetric cell division (unequal distribution of cytoplasmic factors) and local microenvironment cues.
- Noncoding RNAs that regulate mRNA stability or translation.

Example: A stem cell divides to make two identical cells; one receives signals that activate muscle-specific transcription factors, so it expresses muscle proteins and becomes a muscle cell, while the other becomes a neuron or blood cell because of different signals.

Note: Some specialized cells can be reprogrammed (e.g., induced pluripotent stem cells), but in normal development differentiation is largely stable.