And some of these plasmids basically contain the genes that code for proteins which give the cell resistance to drugs and other antibiotics. So basically, conjugation is a type of mating process because it involves two individual bacterial cells. And aside from the circular DNA that codes for most of the bacterial proteins, these bacterial cells contain additional DNA called plasmids. So plasmids, as we mentioned, are small circular DNA that replicate independently of the main DNA molecule and which carry genes that code for proteins that give resistance to drugs. Now, although most plasmids do exist independently of the main DNA molecules, some plasmids can actually incorporate into the main DNA molecule. And such plasmids, such plasmids are known as episodes.