Final answer:
While both bacterial and corn transposons can cause mutations, move to new loci, have inverted repeats, and cause rearrangements, only bacterial transposons typically carry drug-resistance genes in natural populations. This makes option b the correct answer.
Step-by-step explanation:
When comparing the features of bacterial and corn transposons, we can analyze their common characteristics. Both bacterial and corn transposons may cause unstable mutations, may have inverted repeats, may move to new loci, and may cause rearrangements. However, option b, stating that both may carry drug-resistance genes in natural populations, doesn't apply to corn transposons as it does to bacterial transposons.
Bacterial transposons, specifically, can carry antibiotic resistance genes and move them between different genetic contexts, such as from chromosomes to plasmids. This plays a crucial role in the spread of antibiotic resistance among bacteria. For instance, Shigella strains causing bacterial dysentery have shown the colocalization of multiple antibiotic resistance genes on a single R plasmid, which can then be transferred among bacteria by the process of conjugation.
In contrast, corn transposons, discovered by Barbara McClintock, do not naturally carry antibiotic resistance genes in their sequences, as this feature is predominantly associated with the ability of bacteria to survive in environments with antibiotics. Therefore, the correct answer is option b.