The definition of transformation in bacteria is described by the first statement: transformation is the assimilation of external dna into the bacterial cell. In a more elaborate sense, transformation is described by the altering of the cell as a result of the uptake or intentional incorporation of dna from an external source. It is one of the three processes for horizontal gene transfer. The other two are transduction (infection of a phage), and conjugation (transfer of dna between two bacterial cells that are directly in contact).
