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