Final answer:
Transposons constitute a variable, but often substantial, percentage of the maize genome. Class II DNA Transposons make up 100% of all transposons in certain genomic contexts and are significant for understanding genomic DNA.
Step-by-step explanation:
Transposons, often referred to as 'jumping genes', make up a significant part of the maize genome. Discovered by Barbara McClintock, these genetic elements are capable of shifting from one location to another within the genome. While bacteria have few transposons, eukaryotes show a wide diversity in transposon load. Specifically, in the maize genome, transposons can comprise a substantial percentage.
Interesting to note, Class II Transposons (DNA Transposons), which move via the cut-and-paste or replicative pathway, represent 100% of all transposons in certain genomic analyses. Moreover, despite initial scepticism, McClintock's discoveries surrounding transposons have significantly contributed to the field of genetics and our understanding of genomic DNA structure and function.