Summary
Undifferentiated cells capable of self-renewal and of developing into specialised cell types.
In depth
Stem cells divide to renew themselves and produce differentiated progeny. Totipotent cells can form a whole organism, pluripotent cells any body cell, multipotent cells a limited range (such as blood stem cells), and unipotent cells only one type.
Adult stem cells maintain tissues such as gut lining, skin and bone marrow. Their use in therapies raises ethical questions when embryos are involved.
Embryonic stem cells come from the inner cell mass of a blastocyst and can be grown indefinitely in culture, but their use raises ethical questions. Induced pluripotent cells avoid the embryo issue and allow patient-matched cells. Adult stem cells sit in niches that provide signals controlling when they divide.
Therapies already in use include bone marrow transplants for leukaemia and skin grafts grown from stem cells for burns. Challenges include controlling differentiation, avoiding tumours (teratomas), immune rejection and delivering cells where they are needed.
Example: the lining of the small intestine renews every 3 to 5 days from stem cells in the crypts.
Frequently asked questions
What is Stem Cells?
Undifferentiated cells capable of self-renewal and of developing into specialised cell types.
Which area of biology covers Stem Cells, and how advanced is it?
Stem Cells is one of the 52 topics in Cell Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Cell Differentiation, Cell Junctions, Cancer Cell Biology.
Can you give an example of Stem Cells?
Bone marrow transplants rely on haematopoietic stem cells to rebuild the entire blood system.
What should I learn before Stem Cells?
Work through the Beginner topics in Cell Biology first, such as Cell Theory, Prokaryotic Cell, Eukaryotic Cell, then return to Stem Cells. Intermediate topics assume the Beginner vocabulary.
What topics are related to Stem Cells?
The closest topics to Stem Cells are Cell Differentiation, Cell Junctions, Cancer Cell Biology, Apoptosis. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Stem Cells?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Stem Cells. To practise the whole of Cell Biology, use the Cell Biology quiz.
How is Stem Cells different from Cell Differentiation?
Stem Cells: Undifferentiated cells capable of self-renewal and of developing into specialised cell types. Cell Differentiation: The process by which unspecialised cells switch on particular genes to become specialised cell types. Read both side by side and note what each one explains.
How should I study Stem Cells step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Cell Differentiation and explain the difference aloud. Finally, take the Cell Biology quiz and come back to this page for any question you miss.