what is a stem cell

Stem cells are special human cells that have the ability to develop into many different cell types in the body. They are the bodys raw materials, from which all other cells with specialized functions are generated. Stem cells can divide and renew themselves over a long time, and they are unspecialized, so they cannot do specific functions in the body. They have the potential to become specialized cells, such as muscle cells, blood cells, and brain cells. There are two main types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells are pluripotent, which means that they can turn into any cell in the body. These stem cells are obtained from unused embryos resulting from in vitro fertilization procedures, which are donated to science. Adult stem cells, on the other hand, are found in fully developed tissues such as the brain, skin, and bone marrow. They are more likely to generate only certain types of cells. Stem cells have the unique ability to self-renew and to recreate functional tissues. Researchers believe that stem cell-based therapies may one day be used to treat serious illnesses such as paralysis and Alzheimer's disease.