Summary Topic 3 Stem Cells

Stem Cells

cells-undifferentiated
Stem cell
which can divide
and
cell. unlimited
differentiate into a specialised
,
cell division no Mayflick limit
,


S.I units
40-00 limit (specialised cells)
-Hayflick
Telomeresa repetitive nucleotide of
chromosomes to protect the ends
sequences
DNA
on ends

of chromosomes
-
loss of telomeres :
Hayflick limit
Tolomerase preserves telomeres stem cells
kenyth in



Asymmetric cell division
-
one remains a stem cell
One
-



differentiates
Terminally
to become differentiatedcellcompletedall divisionsa on




undifferentiated
Tystem
Res of Tutipotent -
cell which can divide


cell
and
cell type including differentiateintoanyspecialis, , all


Foundin
-




Zygote
up to
day
4 (IW cells) moruth


undifferentiated
Pluripotent -
cell which can divide
and
celL type -
differentiate into
any specialised
excluding embryonic
>

tissues/cells

Found in
-

blastocyst & stage of embryonic cells
-


trophoplast cells
surrounding which
- become placenta

-
inner cell
mass-embryonic stem cell-pluripotent
IVF-fertilise v incubate -
>
blastocyst > needle -
- > harvest