Question

You have a strain of bacteria that is defective for DNA glycosylase activity. You expose one culture of this strain to EMS and the other to cisplatin (a chemotherapy drug that creates bulky adducts on purine bases). You notice that the cisplatin is much more toxic to this mutant strain of bacteria than is the EMS. Explain your observation.

Answer 1

Answer:

Bacteria under successive rounds of selection may acquire genetic resistance to the treatment with mutagenic compounds including ethyl methanesulfonate (EMS).  

Explanation:

Artificial selection is a process known to generate resistance of the organisms under treatment. For example, this type of selection has been reported to generate resistance to the treatment with different chemical compounds including mutagenic chemical compounds (in this case EMS), antibiotic drugs, etc.