New alleles that might allow a bacterium to become resistant to an antibiotic arise through which of the following processes?

• A. Binary fission, where bacteria divide to produce identical daughter cells
• B. Transformation, where bacteria take up foreign DNA from their environment
• C. Conjugation, where bacteria transfer plasmids through direct contact
• D. Transduction, where bacteriophages transfer DNA between bacteria

Answer: (B)

Verified step by step guidance

1. Understand that new alleles in bacteria arise through processes that introduce genetic variation, not through simple cell division like binary fission, which produces identical copies.
2. Recognize that transformation involves bacteria taking up foreign DNA from their environment, which can introduce new genetic material and potentially new alleles.
3. Consider conjugation, a process where bacteria transfer plasmids (small DNA molecules) directly to another bacterium, which can also introduce new alleles if the plasmid carries resistance genes.
4. Examine transduction, where bacteriophages (viruses that infect bacteria) transfer DNA from one bacterium to another, potentially introducing new alleles.
5. Conclude that the processes responsible for new alleles are transformation, conjugation, and transduction, as they all involve horizontal gene transfer, unlike binary fission.