1.5: stem cells Flashcards
1
Q
properties of a stem cell
A
- unspecialised: no tissue-specific structures for specific functions
- long term self renewal: symmetrical/asymmetrical division
- can differentiate: differential gene expression (to assist regeneration)
2
Q
what can totipotent stem cells differentiate into
A
- any cell in the adult body
- including extraembryonic membrane (placenta)
3
Q
where can totipotent stem cells be found
A
zygote
up to 8-cell stage of embryonic development
4
Q
what can pluripotent stem cells differentiate into
A
3 germ layers: mesoderm, endoderm, ectoderm
NOT extraembryonic membrane
5
Q
where can pluripotent stem cells be found
A
inner cell mass of blastocyst
6
Q
what can multipotent stem cells differentiate into
A
multiple but limited types of related cell types
eg haematopoietic (only blood)
7
Q
potency of ZSC
A
totipotent
8
Q
potency of ESCs
A
totipotent
9
Q
potency of ASCs
A
multipotent
10
Q
sources of ESCs
A
- in-vitro fertilisation
- somatic cell nuclear transfer
11
Q
pros of ESCs
A
- divide indefinitely
- differentiate into wide range of cell types
- relatively easily accessible (infertility treatments)
12
Q
cons of ESCs
A
- ethic issues
- potential rejection by patient’s immune system
- cannot control what types of differentiation ESC will undergo
13
Q
source of ASCs
A
- umbilical cord
- specialised tissues and organs (eg bone marrow, brain, liver, skin)
14
Q
pros of ASCs
A
- less ethical controversy
- ASCs will produce specific cell types of tissues (multipotent)
- lowered risk of immune rejection (own body)
15
Q
cons of ASCs
A
- limited quantities
- limited ability to differentiate
- cannot divide indefinitely
