1. Stem Cells and Meristems
National 5
Stem Cells and Meristems
Mr G Davidson

2. Stem Cells
Stem cells are only found in animals and they are unspecialised, i.e. they have no specific function.
They can:
Reproduce repeatedly by mitosis and cell division and remain unspecialised.
Develop into specialised cells when required to replace damaged or old cells.
Wednesday, November 14, 2018
Mr G Davidson

3. Stem Cells There are 2 types of stem cells: Embryonic stem cells.
These are found in very early embryos.
They have the ability to develop into any type of cell the body requires.
They can even develop into complete organs.
Wednesday, November 14, 2018
Mr G Davidson

4. Stem Cells Adult stem cells.
These are sometimes called tissue stem cells and don’t have the same regenerative powers as embryonic stem cells.
They can usually only regenerate cells associated with the tissues in which they are found.
Wednesday, November 14, 2018
Mr G Davidson

5. Uses of Stem Cells
Stem cells have some very important medical applications and stem cell technology is a rapidly developing field in modern biology.
Some important medical applications of stem cells include the following:
Wednesday, November 14, 2018
Mr G Davidson

6. Medical Application of Stem Cells
Bone Marrow Transplant
Used to treat some forms of blood cancer such as leukaemia.
White blood cells divide uncontrollably.
The patient has the cancerous bone marrow cells destroyed and replaced with blood forming stem cells.
Wednesday, November 14, 2018
Mr G Davidson

7. Medical Application of Stem Cells
Skin Grafts.
Traditional skin grafts involve removing a layer of skin from one part of the body and covering another damaged part.
Using stem cells, they are cultured to allow them to multiply, and then sprayed on the damaged skin to allow the skin to regenerate.
Wednesday, November 14, 2018
Mr G Davidson

8. Medical Application of Stem Cells
Repairing Heart Muscle
Although this is still being tested, it is hoped that in future stem cells will be used to repair heart muscle after a heart attack.
Wednesday, November 14, 2018
Mr G Davidson

9. Medical Application of Stem Cells
Cornea repair
Stem cells from the patients themselves can be grown and then transplanted onto the surface of the eye to treat damaged corneal cells.
Wednesday, November 14, 2018
Mr G Davidson

10. Medical Application of Stem Cells
Future applications of stem cell technology.
Diabetes
Alzheimer’s disease
Stroke victims
Parkinson’s disease
Multiple sclerosis
Spinal-cord injuries.
Wednesday, November 14, 2018
Mr G Davidson

11. Stem Cells – The Issues
There are many issues surrounding stem cells and their uses.
Many people disagree with the use of embryonic stem cells as the embryo is destroyed.
Some would argue that the embryos are excess and would be destroyed anyway.
Wednesday, November 14, 2018
Mr G Davidson

12. Stem Cells – The Issues
Stem cell technology is very similar to cloning which has its own issues.
Safety concerns.
Some people are uncomfortable with mixing genetic material from different species.
It is important to remember that there is more than one side to every argument.
Wednesday, November 14, 2018
Mr G Davidson

13. Meristems
Unlike animals, where growth stops upon reaching adulthood, plants continue to grow throughout their lives.
However, this growth is restricted to specific areas of the plants known as meristems.
Meristems are found at the root tips and the shoot tips of plants.
Wednesday, November 14, 2018
Mr G Davidson

14. Meristems
The cells here are non-specialised with the potential to grow into whatever cells the plant needs.
Cells in the meristems divide by mitosis.
Some of these cells remain unspecialised to continue to produce new cells.
Wednesday, November 14, 2018
Mr G Davidson