stem cells Flashcards
two characteristics of stem cells
capable of self-renewal: can replicate themselves as new stem cells or differentiate into distinct cell types. are able to divide indefinitely to replace cells.
What are stem cell niches?
An area of tissue that provide micro environments made up of specialised cell structures that protect the stem cells.
What do niches do?
They regulate the rate of cell growth/replication that is specific to the body part and stem cells.
When stem cells lack a niche, they either die or differentiate. True or false.
True
Name the two types of stem cells.
Embryonic and adult
Describe embryonic stem cells.
It is the undifferentiated or relatively undifferentiated of embryos from the zygote to blastocyst stage. Can be obtained from surplus 3-5 day old embryos from IVF programs.
Ethical concerns surrounding the use of embryonic stem cells.
The use of these stem cells involve the destruction of human embryos, which destroys the potential of new human life.
Name two differences between embryonic and adult stem cells.
- can / cannot replicate indefinitely
- esc can differentiate into any cell type while asc can only give rise to a limited range of cells
What is the biological purpose of adult stem cells?
to repair and regenerate damaged or aged tissues (eg. skin, liver cells)
Name three parts of the body where adult stem cells can be found.
hair follicles, bone marrow, spinal cord
Stem cells remain undifferentiated throughout a person’s life. True or false.
True
What is cell potency?
the ability of cells to differentiate into other cell types; more cell types, higher the potency
Describe totipotency.
able to give rise to any cell type or even another embryo or placenta. zygote to 16 cell morula stage.
Describe pluripotent cells.
Can differentiate into any cell type in the three germ layers. Blastocyst stage.
Describe the three germ layers.
endoderm: lung, gut lining
mesoderm: muscle, bone, blood
ectoderm: skin, nerve cells
Describe multipotent cells.
has the ability to give rise to multiple, but limited cell types.
Describe unipotent cells.
can only differentiate into one cell type found in a specific tissue but can divide repeatedly.
What is iPSC?
induced pluripotent stem cells. they are genetically programmed to become embryonic stem cells again, expressing the genes and characteristics of an esc. Less ethical considerations as they made modified in a lab.
