Stem Cells
Undifferentiated cells that keep dividing and therefore can give rise to other cell types and are totipotent
Healthy stem cells can be used to provide ill patients a better chance of recovery as they can stimulate a person's body to help repair itself
Have limited uses
Hard to find and extract
Can be rejected from a patients body
Embryonic Stem Cells
Can produce any of the human cells
Pluripotent
Uses
Could be used to treat some medical conditions that involve cell loss/damage
Parkinson's
Multiple Sclerosis (electrical insulation of nerve cells is lost)
Type 1 Diabetes
Burns
Ethical Issues
When does an embryo become a human?
Is it acceptable to use a human embryo for this research?
Is it acceptable to fuse an adult Stem Cell with a human egg to create ne stem cells? (cloning)
Therapeutic Cloning
problem with transplanting organs is that they can be rejected
if the organ is grown from a person's own cells this problem is avoided
Diploid cell is removed from a patient needing a transplant
Cell's nucleus is fused with an ovum from which haploid nucleus has been removed from and a diploid cell results (Somatic Cell Nuclear Transfer)
Stem cells arising from this could be encouraged to become whatever tissue is needed
Who Decides
Society uses scientific knowledge to make decisions about the use of stem cells in medical therapies
Decisions are made by:
- People working within the field
- Everyone else (range of views)
Final decisions are made by regulatory authorities e.g. Human Fertilisation and Embryology Authority (UK)
How stem cells become specialised
Chemical signals cause some genes to be activated
only the activated genes produce mRNA
mRNA leads to synthesis of specific proteins which cause cell modification