This figure is a schematic representation of the differences between horizontal and vertical gene transmission. On the left of the figure is a blue oval representing a bacterial cell. This cell contains a blue wavy line labelled chromosomal DNA and a red circle labelled resistance plasmid. On the blue wavy line there is a small orange region labelled resistance gene. There is an arrow going from the blue bacterial cell to a green oval representing another bacterial cell. The arrow is labelled horizontal transfer. The green cell contains a green wavy line labelled chromosomal DNA and a red circle labelled resistance plasmid. On the green wavy line there is a small red region labelled resistance gene. Below this cell is another cell which is identical except that the chromosomal DNA is duplicated. The image below this is of an elongated, squashed green cell containing two copies of the chromosomal DNA and one resistance plasmid. The final image is of two green cells. One cell contains only chromosomal DNA, the other cell contains chromosomal DNA and the resistance plasmid. There is a vertical arrow running from the first green cell at the top to the two green cells at the bottom. It is labelled vertical transfer.