Practice question

Cut-and-paste transposition is hallmark of Class II DNA transposons where transposase excises element from donor chromosome and integrates into new target site, physically relocating sequence rather than copying. Reaction involves binding terminal inverted repeats, forming transpososome synaptic complex, double-strand cleavage at donor ends, target capture with staggered cuts, and strand transfer followed by gap repair duplicating target site. Net result is element movement without increase in number per simple event, though homologous recombination repair can duplicate element explaining spread. This principle illustrates essential molecular mechanisms governing replication fidelity and mutation fixation relevant for exam interpretation.