What is a stem cell?
A cell must meet two basic key criteria in order to be considered a stem cell:
1. Able to differentiate into multiple cell types upon induction.
2. Able to remain in an undifferentiated state over numerous cell divisions when not induced to differentiate.
There are numerous "stem cells", some with more potential than others. An embryonic stem cell is pluripotent by definition because it is able to become any cell in the body (though this is difficult in practice). Other stem cells are more restricted, such as the hematopoietic stem cell, which can only form the cell types found in blood and the immune system.
A new form of cell called an induced pluripotent stem cell (iPS), can be generated by turning on at least 2 specific genes in skin or other non-stem cells. This is commonly done through use of a viral vector such as a retrovirus although it is now possible to avoid the use of virus. Preliminary studies indicate that iPS cells have identical capabilities as embryonic stem cells which may negate the need to derive embryonic stem cells from embryos. Still, everything we know about pluripotent stem cells comes from studies of embryonic stem cells and thus they are an integral part of the quest for therapeutic uses for stem cells.
a regular cell is natural ???????? right? A stem cell is a cell that can renew themselves to form other types of cell. Example:Human egg cell/ovum This is an example of a totipotent stem cell. Totipotent stem cells are those cells that can transform into any type of cell. There are many types of stem cells like pluripotent stem cells, multipotent stem cells etc.
There are three types of stem cells. they are 1)Totipotent 2)Pluripotent 3)Multipotent. Totipotent: Stem cell that can become any kind of cell in the body. Ex:- Embryonic stem cells. Pluripotent: Stem cell that can become almost any kind of cell in the body. Ex:- Blastocyst embryonic stem cells, fetal stem cells. Multipotent: Stem cell that can differentiate into only a limited range of cell types. Ex:- Umbilical cord stem cells, adult stem cells
The main difference between a stem cell and a differentiated cell is: A stem cell has the ability to self-renewel and also has the ability to differentiate(to become a tissue specific cell). But, a differentiated cell don't have the ability to self-renewel(moreover a stem cell get specialised to a differentiated cell).
Stem cells are considered as undifferentiated cells. They will divide and divide forming more stem cells. The two main stem cell types are embryonic stem cells and adult stem cells. Only the embryonic stem cells can become any type of tissue. Embryonic stem cells have the potential to become any type of cell in the body. There is news as of 2015 that perhaps blindness can be cured using these embryonic stem cells.