Transposable elements have been found only in procaryotes and do not appear to play a major role in eucaryotic genetics. Each antibiotic resistance gene is carried on a single plasmid. Hfr strains can be used to map the entire bacterial genome by constructing overlapping maps from Hfr strains with different integration sites. When a genome is mapped with Hfr conjugation, a high frequency of gene transfer means that the gene is located close to the integration site of the plasmid. Transformation has been observed in only a limited number of species in nature, but we have found ways to force the process upon other species in the laboratory.
All resistance plasmids are nonconjugative.
D. All are equally error-prone.