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Specialised cells usually retain much of the same DNA but use different parts of it. Distinguish a cell’s developmental potential from the functions it currently performs.
Video by Cognito. The video’s own board label is retained; follow the specification reference and scope notes on this lesson for assessed content.
Viewing focus: Compare totipotent, pluripotent, multipotent and unipotent cells
After watching, attempt these questions before opening the answers. You can also use the written lesson below.
After watching 1: Pluripotency concerns the ability to:
Generate the body’s different cell types. Developmental potential requires appropriate conditions and differentiation.
After watching 2: Most cell specialisation is associated with:
Different patterns of gene expression. Shared DNA can produce different cellular programmes.
What you'll be able to do
Totipotent early embryonic cells can contribute to the cell types needed for a complete organism, including appropriate extraembryonic tissues in the full biological definition. Pluripotent cells can form the body’s different cell types but do not by themselves have the same complete developmental potential.
Multipotent cells generate several related cell types within a restricted range, while unipotent progenitors form one lineage. The specification uses formation of cardiomyocytes as its unipotent example; this does not mean every mature heart-muscle cell can divide freely. Potential is not the same as currently expressing every gene at once. A differentiated cell has a specific pattern of gene activity and proteins that supports its function.
During development, cells with broadly the same genome can activate different genes and produce different proteins. This creates structural and functional specialisation without requiring removal of every unused gene. Regulatory proteins and epigenetic states help maintain cell identities.
Induced pluripotent stem cells can be produced by reprogramming adult somatic cells using suitable transcription factors. This changes the regulatory state and developmental potential; it does not mean every original DNA mutation has been corrected. Reprogramming and controlled differentiation are distinct steps in any proposed application.
Stem-cell approaches could provide replacement specialised cells, disease models or systems for testing biological responses. A useful proposal must show that cells differentiate appropriately, integrate and function, and do not proliferate uncontrollably. Laboratory potential is different from demonstrated long-term effectiveness in a patient group.
Compare evidence about immune compatibility, genetic integrity, tumour risk, practical production and the source of cells. Ethical evaluation includes consent, embryo use where relevant, access and the quality of claimed benefits. Avoid either “all stem cells can make everything” or “all stem-cell uses are identical”; the cell type and intended role matter.
Try each question before opening the worked response. Use precise biological terms, connect each cause to its effect, and check units and assumptions when interpreting data.
Common mistakes to avoid
Key takeaways
Check the assessed scope and practical or mathematical requirements.
An external explanation or interactive activity to use alongside the lesson. It may include extension material.
Close the notes and answer from memory. Revisit any explanation you cannot yet reconstruct.
Test yourself
Answer a few questions, then review anything you missed.
Start with the quiz above to check the key ideas. You can also choose another topic from the practice library.