Introduction to Stem Cells
What is a stem cell?
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Master cell.
Undifferentiated (unspecialised cell type).
Found in all multicellular organisms.
Self-renewing and can differentiate.
Can you give examples of differentiated
cells and their functions?
Embryonic stem cells
• Totipotent:
toti = total
potent = capacity
• The state of the cells
after the first few
divisions of the
fertilised egg.
• Have the capacity to
become all cell types
plus placenta.
Embryonic stem cells
• Pluripotent:
pluri = many
potent = capacity
• At blastocyst stage
cells become
pluripotent.
• Have the capacity to
become all cell types
but not placenta.
• Cells of most interest
to research scientists.
Adult stem cells
• Multipotent
• Can develop into cells
that are closely related.
• Limited number of several
cell types.
• Make all cell types from
the tissue they come
from.
• Found in many parts of
the body.
• Can self-renew over a
lifetime.
Focus questions
• What is the unique property of stem cells
which makes them different from a
specialised cell?
Focus questions
• What does it mean when we say a cell has
become ‘differentiated’?
Focus questions
• Embryonic stem cells are described as
pluripotent whereas adult stem cells are
multipotent. Describe in your own words
what these terms mean.
Focus questions
• Why does adult tissue need stem cells?
Focus questions
• Why are research scientists so interested
in using stem cells?
Focus questions
• We have discussed several types of stem
cells. Which type do you think would be
most useful to treat human disease? Give
a reason for your answer.
Focus questions
Each group has to investigate a disease
that could be treated with stem cells. For
the disease the group has identified:
• describe the condition
• identify the organ/system affected
• give a reason for why stem cells rather
than drug therapy would be beneficial.