Final answer:
Cell differentiation is the last developmental stage of a cell, where it becomes specialized and gains unique functions, facilitated by transcription factors controlling gene expression.
Step-by-step explanation:
The last stage in a cell's development, when its pattern of gene activity differs from any other cell is cell differentiation. This is the phase where unspecialized cells become specialized and assume distinct functions, structures, and metabolic activities. During cell differentiation, cells undergo profound changes that determine their specific roles in the body's makeup. A stem cell is a great example of an unspecialized cell that, under certain conditions, has the ability to differentiate and become a specialized cell, such as a nerve cell, muscle cell, or epithelial cell. The process involves certain transcription factor proteins that control gene expression by facilitating or hindering the transcription of genes, dictating the unique features of each cell type