Stem Cells

Stem cells are very important, they are mainly Adult Stem Cells and Embryonic Stem cells.

There are mainly two key features of stem cells, one of them is that they can divide by Mitosis, and the other key feature is that they are able to differentiate or turn into specialised cells, one can split and turn into a skin cell, or a blood cell.  

When a Sperm cell fertilises an egg cell. It forms a Zygote, then it undergoes mitosis and forms an Embryo, these are embryonic stem cells.
These cells are embryonic so they can differentiate into any kind of cell, nerve cell, skin cell, brain cell, and in time differentiate into different kinds of cells, then after 9 months, we have an infant baby.

Now let's move to an adult, their stem cells are very different from embryonic stem cells because they can only differentiate into a more narrow range of cells. 
These cells are more specialised, like bone marrow which is inside of our bones and contains adult stem cells, but since they are more specialised, they can only turn into cells. Red blood cells, Platelets and White blood cells, these cells can keep us alive, but they don't form any new tissues. 

Now plant stem cells are a little different known as Meristems found on roots and tips of shoots, as these stem cells are found where the plant is still growing, these stem cells are still persistent and are still used throughout the plant's life, unlike our stem cells when we reach adulthood.

If we can change these damaged or faulty cells, with new cells we can treat these ailments. 
In order to get these stem cells, scientists first gather embryonic cells, then grow them in a laboratory, then stimulate them into the type they want, and then give them to the patient who needs the stem cells.