Embryological Development

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Embryological Development

• and Stem Cells

ByJewel Reuter, LA Virtual SchoolDonald
Cronkite, Hope College
Attachment 12
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Two Kinds of Cells
During embryological development, cells divide
again and again.
Eventually, however, cells differentiate. Most
differentiated cells do not divide.
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But if no cells divided
Some cell division is always necessary to
Make more blood cells
Heal wounds
Make a continuous supply of sperm cells
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So there are stem cells. . .
Stem cell keeps dividing
differentiate
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In early embryos, most cells are stem cells.
Bgn1
Inner cell mass (becomes the embryo)
Compared to the more than a trillion cells in an
adult, the inner cell mass is scarcely 100 cells.

The blastocystA week-old embryo
The inner cell mass must give rise to many
different cell types. All the inner cell mass is
made of stem cells.
This membrane of cells attaches the embryo to the
mother.
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Stem cells vary in what they become.
Bgn2
Embryonic stem cells Can become any cell (Inner
cell mass of blastocyst)
Adult stem cells Can become a few cell
types (Blood-forming, wound- healing,
sperm-forming cells)
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Stem cells can be cultured.
Bgn3
With the right medium, stem cells can be cultured
in dishes. Scientists are learning how to get
a stem cell to differentiate into a certain cell
type.
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What could we do with stem cells?
Diabetes cells of the pancreas
Parkinsons disease cells of the brain
The bubble boy cells of the immune system
Many diseases are due to cells that wont work.
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What could we do with stem cells?
Diabetes cells of the pancreas
Parkinsons disease cells of the brain
The bubble boy cells of the immune system
What if we could replace the cells that wont
work with new ones made from stem cells?
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This is the end of this lesson,

• but not the end of your learning.

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In early embryos, most cells are stem cells.
ADV1
Inner cell mass (becomes the embryo)
Compared to the more than a trillion cells in an
adult, the inner cell mass is scarcely 100 cells.

The blastocystA week-old embryo
So, the inner cell mass must give rise to many
different cell types. All of the inner cell
mass is made of stem cells.
Trophoblast(becomes part of placenta)
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Stem cells vary in what they become.
ADV2
Totipotent stem cells (the inner cell mass of
blastocyst) can become any cell.
Pluripotent stem cells can become a few cell
types, such as blood-forming, wound- healing,
sperm-forming cells.
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Stem cells can be cultured.
ADV3
With the right medium, totipotent or pluripotent
stem cells can be cultured in dishes.
Scientists are learning how to get a stem cell
to differentiate into a certain cell type.