Some bacterial transposons, known as Tn elements, are larger than insertion sequences (IS elements) and contain protein-coding genes that have human health significance. What might such a bacterial transposon contain?

One type of mutation involves the replacement of a purine with a purine, while another causes the replacement of a pyrimidine with a purine or the reverse. What general terms are associated with these two mutational phenomena?

List five general categories of mutation.