Acquired resistance may be totally resistant in some bacteria or cancer cells.

Acquired resistance may be totally resistant in some bacteria or cancer cells.

• A. False
• B. True
• C. Not determinable
• D. Not applicable

Answer: (B)

Acquired resistance can become totally resistant in some bacteria or cancer cells. When resistance develops after exposure, it can arise from mutations or new genes that either inactivate the drug, alter the drug’s target, or pump the drug out of the cell. In bacteria, acquiring resistance genes on plasmids or chromosomal changes can produce very high-level or even complete resistance to an antibiotic, especially if multiple mechanisms pile up. In cancer, tumor cells can gain changes that disable the drug’s effect—such as increased drug efflux, target modification, or enhanced DNA repair—so a clone of cells may become unresponsive to therapy as a whole. While resistance can be partial or multi-faceted, it is possible for a population to become totally resistant to a given treatment, which is why this statement is true.

Acquired resistance can become totally resistant in some bacteria or cancer cells. When resistance develops after exposure, it can arise from mutations or new genes that either inactivate the drug, alter the drug’s target, or pump the drug out of the cell. In bacteria, acquiring resistance genes on plasmids or chromosomal changes can produce very high-level or even complete resistance to an antibiotic, especially if multiple mechanisms pile up. In cancer, tumor cells can gain changes that disable the drug’s effect—such as increased drug efflux, target modification, or enhanced DNA repair—so a clone of cells may become unresponsive to therapy as a whole. While resistance can be partial or multi-faceted, it is possible for a population to become totally resistant to a given treatment, which is why this statement is true.