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. So if we take a look at the following prokaryotic cell arabacterial cell, this is the main DNA molecule of our cell. And this smaller one is Aroplasmid. Now, what's the big deal with plasmids and conjugation?