stem cells

Stem cell

An undifferentiated cell which can become any type of cell

Undifferentiated

A cell which is not yet specialised

Differentiated

A cell which is specialised to a specific function

Human embryo

A source of stem cells which can become any type of cell

Bone marrow

A source of stem cells which can become many types of cell including blood cells

Meristem

The region in plant shoots and roots where mitosis occurs and a source of stem cells in plant tissue

Diabetes

A disease of the pancreas which may be treated with stem cells

Spinal cord injury

A cause of paralysis which may be treated with stem cells

Therapeutic cloning

When an embryo is produced with the same genes as the patient as a source of stem cells

Potential risks of stem cell treatment

Viral infection, cancer and rejection unless therapeutic cloning is used

Cloning rare plant species

A way of protecting plant species from extinction, using meristem tissue

Cloning disease resistant crops

A way of providing food security, using meristem tissue

Zygote

A fertilised egg cell which divides to form an embryo

Ethical objections

Moral reasons people may be against stem cell treatments

Religious objections

Religious reasons people may be against stem cell treatments

Advantages of bone marrow stem cells

Can treat many blood-linked or immune-linked diseases, less ethical concerns than embryonic stem cells, bone marrow is easier to obtain than embryonic cells

Advantages of embryonic stem cells

No consent required, obtainable via embryos discarded in IVF, can be used to make any type of cell, less risk of rejection if used via therapeutic cloning

Disadvantages of bone marrow stem cells

Requires voluntary donors, bone marrow extraction can cause pain to an individual and requires consent, may have a risk of infection, can only form cells such as blood cells, risk of rejection

Disadvantages of embryonic stem cells

Ethical considerations such as potential loss of life or harm to embryo, less easily obtainable than bone marrow stem cells, risk of rejection