What is the role of plasmids in bacterial transformation?

Plasmids play a central role in bacterial transformation as they serve as the vehicle for introducing foreign DNA into bacterial cells. These small, circular DNA molecules can replicate independently of the bacterial chromosome and often carry genes of interest, such as those conferring antibiotic resistance or encoding desired proteins. Plasmids are engineered with specific features, such as promoters and selectable markers, to ensure efficient gene expression and identification of successfully transformed cells.