Dr. William H. Heidcamp, a professor in the Biology Department at Gustavus Adolphus College, explains that cell differentiation occurs when the structure and function of cells change within a certain period. The formation of the three germ tissues of embryos, which are the endoderm, ectoderm and mesoderm, is a classical approach to the basic process of cellular differentiation.
According to Kenyon College, differentiation occurs after determination of different cell types, which involves progressive restrictions in their developmental potentials. The result of differentiation is the presence of cell types with clear identities, such as skin cells, nerve cells and muscle cells.
Molecular Devices explains that in cell differentiation, triggers from the body or the cell itself lead to the development of a generic cell into a particular type of cell. This process enables a single-celled zygote to develop into a multicellular adult organism with hundreds of various types of cells. Cell differentiation is critical to embryonic development. Moreover, it is important in the function of organisms, especially complex organisms. Due to differentiation, a cell dramatically changes its shape, size, metabolic activity, responsiveness to signals and membrane potential. These changes occur because of highly controlled modifications in gene expression. Different cells develop different physical characteristics, although they have the same genome.