Prokaryotes are unicellular (single-celled) organisms and on the other hand Eukaryotes are multicellular organisms and more developed in organ and structure compared to prokaryotes. Gene regulation is key to both organisms as it determines growth and development and other process and activities performed by the organism. However, the two organisms differ in the way they regulate their genes. Prokaryotes cells lack nucleus while the eukaryotic cells have a well defined nucleus. In Prokaryotes RNA transcription and protein formation occur almost simultaneously while in the Eukaryotes RNA transcription occur before the protein formation in the nucleus and then protein formation occurs in the cytoplasm. In addition both organisms uses the same processes in gene regulation and only differ in the manner the processes are undertaken. Lastly, gene expression in prokaryotes is regulated at transcriptional level whereas in eukaryotes regulation is at many levels.