FIGURE 8-11 Mechanism for increasing DNA-transposon copy number. If a DNA transposon, which transposes by a cut-and-paste mechanism (see Figure 8-10), transposes during S phase from a region of the chromosome that has replicated to a region that has not yet replicated, then when chromosomal replication is completed, one of the two daughter chromosomes will have a net increase of one copy of the transposon.