A Scientific Explanation of Stem Cells and Stem Cell Research

In general, a cell can be defined as a stem cell if two basic criteria are met. First, stem cell is capable of self renewal for indefinite period throughout life while maintaining undifferentiated state, i.e., the cell can divide and produce two identical daughter cells and thereby maintains the stem cell pool. Second, stem cell possesses capacity for differentiate into specialised and functional progeny under the right conditions, or given the right signals. It may divide asymmetrically to yield an identical cell and a daughter cell that acquires a particular cell type’s properties, such as morphology, phenotype and functional physiology that classified it belongs to a particular tissue (Burns and Zon 2002; Preston et al. 2003).

Stem cell also can be classified into a hierarchy according to its differentiation potential (Figure 1). On the very top of the hierarchy is the totipotent stem cell. This cell is able to give rise to all kind of cell which constitute the embryonic and extra-embryonic tissues and then contribute to the entire organism, (e.g. the fertilized egg or zygote)...