Final answer:
The ends of a transposon are signified by inverted repeats, and enzymes such as transposase recognize these repeats to facilitate transposon movement within the genome.
Step-by-step explanation:
The structural element that signifies the ends of a transposon are generally inverted repeats and are recognized by specialized enzymes such as transposase. These enzymes facilitate the movement of the transposon within the genome. The transposase makes staggered cuts at these inverted repeat sites, holds the transposon ends together, and inserts the transposon at a new location in the genome. The insertion site is then flanked by direct repeats that are generated due to the transposition process.
For example, in bacterial Insertion Sequences (IS elements), inverted repeats at the ends of the transposon are flanked by direct repeats of host genome DNA that arise from the transposition mechanism.