1.+Stem+Cells

=**What is a stem cell:**=

[|Stem cells] have the remarkable potential to develop into many different cell types in the body during early life and growth. In many tissues they work as an internal repair system to replenish other cells as long as the person or animal is alive. When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell. [|Stem cells] are distinguished from other cells. One important characteristic is that they are unspecialized and can reproduce themselves through cell division. The other important characteristic is that they can become organ- or tissue-specific cells.

=**What are some different types of** stem cells**?**=

Early Embryonic [|Stem Cells]: - the first step : the fertilized egg begins to divide, producing a group of [|stem cells] called an embryo. This early [|stem cells] are totipotent - they can become any kind of cell in the body. Blastocyst Embryonic [|Stem Cells]: - seven days after fertilization the embryo forms a blastocyst. The [|stem cells] in the blastocyst are pluripotent, meaning that they have the ability to become almost any kind of cell in the body.

Fetal [|Stem Cells]: - after the eighth week the embryo is referred to as a fetus. By this time it has developed a human-like form. Fetal [|stem cells] are also pluripotent.

Umbilical Cord (Nabelschnur) [|Stem Cells]: - After birth, the umbilical cord is removed from the infant (Baby), leaving a bellybutton (Bauchnabel) in its place. Blood from the umbilical cord contains [|stem cells] that are genetically identical to the newborn child. Umbilical cord [|stem cells] are multipotent, meaning that they can´t become any kind of cell in the body.

Adult [|Stem Cells]: - Infants and children also have them. There are Blood cells, Nerve cells, Muscle cells, Bone cells, Skin cells. Adult [|stem cells] are also multipotent.