Bacterial genetics entails the study of bacterial genome and various modifications and interference to the natural bacterial genetic make-up. Bacteria have proved to be an essential part of modern genetics and have allowed researchers to understand various mechanisms that occur in human genetics, using bacteria as a model. An example of which would be an insight into how gene transcription is controlled (how genes are turned on and off/ expressed in varying levels) using the Lac Operon as a model. Bacteria used in bacterial genetics are generally haplpoid organisms, i.e. one copy of an allele which produces an immediate effect on a phenotype. In most casesplasmids are used to transfer genes from donor to recipient, which can replicate independently.