Stem cells are cells that have NOT yet been differentiated. They are not yet specialized. Some cells do not become specialized yet, but are called undifferentiated.
Undifferentiated cells have not yet undergone changes to become specialised for a particular function. They are called stem cells. Stem cells are capable of multiplying, resulting in more undifferentiated cells. In addition, they can develop into different types of cells, depending on what instructions they receive.
Human embryonic stem cells are found in early stages of development. Doctors and medical researchers are interested in them because they can turn into any type of cell. If you think about it, all the different types of cells found in a human being are derived from those few cells in the early embryo.
Adults also possess stem cells, but they are only found in certain places, such as the bone marrow. These cells are not as versatile as embryonic stem cells; they can only turn into certain types of cells, such as blood cells.
Stem cells from embryos and bone marrow can be grown in a lab to create genetically identical clones, which can then be differentiated into specialised cells for use in medicine or research.
Embryonic stem cells in medicine
A type of cloning called therapeutic cloning allows an embryo to have the same genetic information as the patient. As a result, stem cells produced from it would contain the same genes as the patient and could therefore be used to replace damaged cells without being rejected by the body.
The use of stem cells in medicine is not without risks. As an example, stem cells grown in the lab may become contaminated with viruses that could then infect the patient and cause them to become ill. Ethical concerns also surround the use of embryonic stem cells.
Issues with stem cells
There are exciting possibilities with embryonic stem cell research, but it is also highly controversial. There are some people who oppose this because they believe that human embryos should not be used for experiments because each one is a potential human life.
However, some people think that treating patients who already exist and who are suffering is more important than the rights of embryos. One argument in favor of this viewpoint is that the embryos used in research are often unwanted ones from fertility clinics, which if not used for research would likely just be discarded. Nevertheless, campaigners for embryonic rights usually oppose this as well.
Stem cell research is banned in some countries, but it's allowed in the UK as long as strict guidelines are followed.
Stem cells in plant life
Stem cells in plants are found in the meristems, the parts of a plant that are responsible for growth. Any type of cell can develop in the meristem tissues of a plant throughout its lifetime. It is possible to produce clones of whole plants quickly and cheaply using stem cells.
Revision Quiz for Stem Cells
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