Final answer:
Cell differentiation is the process by which cells from a fertilized egg specialize into various cell types with unique functions, through the regulation of gene expression.
Step-by-step explanation:
Cell Differentiation and Specialization
As a fertilized egg divides and develops into a complex organism, the process of cell differentiation occurs. This biological mechanism allows cells to become specialized, adopting unique structures and functions necessary for the organism's growth and development. Essentially, the original cell, or zygote, is a totipotent stem cell, which then differentiates into various cell types like nerve cells, muscle cells, and epithelial cells. Cell differentiation is achieved through unique gene expression, where cells activate only the parts of their DNA that are relevant to their specific function, much like actors in a movie reading only their part of a script.
Stem cells, particularly those involved in early embryonic development, play a pivotal role by dividing and differentiating into the specialized cells required for the organism's development. These stem cells are divided into categories based on their potential to differentiate. The interplay of transcription factor proteins regulates which genes are expressed, guiding the stem cells through a path to become distinct cell types with dedicated roles within the body.
It is crucial to recognize that all cells contain the same DNA, but differentiation dictates that each cell type will express only a subset of genes. This selective gene expression is responsible for the diversity of cell functions that enable the multitude of biological processes within an organism.