stem cells

• What is a stem cell?

  An unspecialised/ undifferentiated cell which differentiates to become a specialised cell which are adapted to perform a specific function.
• Name 2 types of stem cell

  Adult stem cells

  Embryonic Stem Cells
• What happens when a cell divides?

  Every time a stem cell divides, it either produces another stem cell or it differentiates to produce a specialised cell
• What is a zygote?

  It is single celled. It undergoes mitosis making identical copies of itself until it forms a hollow ball of cells. This is an embryo.
• What are adult stem cells?

  Not fully specialised

  Good source in bone marrow

  They can differentiate to form all blood cells

  HOWEVER, they cannot form other cells such as brain, liver, muscle etc.
• Describe how Adult and Embryonic stem cells are different.

  Adult stem cells are already specialised whilst embryonic stem cells are completely undifferentiated. They are sourced in different locations.
• How can stem cells be used to treat disease?

  They can be injected into different parts of the body and differentiate to perform a specific function.
• Name arguments for the use of embryonic stem cells

  - Come from aborted embryos or left over from fertility treatments

  - Can become any type of cell

  - Although adult stem cells may be rejected by the immune system
• How can stem cells be used to treat disease?

  They can be injected into different parts of the body and differentiate to perform a specific function
• Name scientific arguments against stem cells

  - Difficult to persuade into differentiating as signals needed are not completely understood

  - there are concerns that as stem cells divide rapidly, they could cause cancer
• Name the ethical arguments against stem cells

  - The embryo cannot give permission for its cell to be used

  - It destroys the embryo so it destroys potential human life

  -Some religions don't accept any interference with the process of human reproduction
• Name the areas of medical research where we can use stem cells

  - Spinal Cord injury

  - Diabetes

  - Heart after damage in a heart attack

  - Eyesight in the blind

  - Damaged bone and cartilage
• Describe how Adult and Embryonic stem cells are different.

  Adult stem cells are already specialised whilst embryonic stem cells are completely undifferentiated. They are sourced in different locations.
• where are stem cells found in plants?

  the meristems.
• when can stem cells differentiate in plants?

  Throughout their entire life cycle. cells in the meristem tissues can differentiate into any type of plant cell.
• what can stem cells in plants do?

  they can be used to produce clones of whole plants quickly and cheaply
• what is the use of stem cells in plants?

  • they can be used to grow more plants of rare species (to prevent them being wiped out)
  • stem cells can also be used to grow crops of identical plants that have desired features for eg disease resistance.