In many organisms cells are specialized (differentiated) for particular tasks. Muscle cells and liver cells, for example, perform different functions although they both have the same genes. In a muscle cell, the genes for muscle cell function are active but the genes for other functions are inactive. Regulating gene activity can be accomplished by controlling the transcription/translation process. Prokaryotes, the bacteria, and eukaryotes, all other organisms, regulate gene expression in different ways.