The bacterium ultraviolet Deinococcus radiodurans is extremely resistant to ionizing radiation, ultraviolet, peroxide and many other agents that damage DNA. Studies show that this resistance is due to Deinococcus radiodurans's extremely proficient and accurate DNA repair process. Our knowledge of this process is rudimentary. There are three types of DNA repair in Deinococcus radiodurans : base excision repair, nucleotide excision repair and recombinational repair. There is argument on whether Deinococcus radiodurans possesses SOS repair. In addition, chromosomal DNA degradation contributes to the accuracy of DNA repair in Deinococcus radiodurans .