Download Stem Cells

10.4
Cell Differentiation
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Differentiation – cells become different; form
into many types of cells
Become specialized for certain tasks
Stem Cells
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= Unspecialized cells from which other cells
develop
Totipotent – can develop into any kind of cell in
body (ex. First fertilized cells)
Blastocyst – hollow ball of cells; early embryo
Pluripotent – inside blastocyst; can develop into
most types of cells (not the tissue around
embryo)
Types
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Embryonic stem cells – research shows can
form into any cell type in human body
Adult stem cells – “pools” to replenish
damaged/dead cells
* Are multipotent  typically develop into
cells from the type of tissue they originated
* Ex. Bone marrow transplants = stem cell
transplants for blood
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Adult cells altered to have properties of
embryonic stem cells = induced pluripotent
stem cells; still unknown effects in humans
Amniotic fluid stem cells – need more research
Stem Cell Research
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Benefits – replace injured cells/tissues
Ex. Heart cells, brain cells, nerve cells
Ethics –
* Adult stem cells – fine
* Embryonic stem cells – destroys embryo