Question 1
Multiple choiceEasy1 markA hospital restricts antibiotics to cases in which they are needed. Some pathogenic bacterial strains are already resistant to several antibiotics. How can this careful use slow the increase of multiresistant strains?
Show answer and explanation
Answer: D. Antibiotic use selects for resistant bacteria because susceptible bacteria are more likely to be killed. With less unnecessary antibiotic use, the selective advantage of multiresistant bacteria is reduced, slowing their increase in frequency.
A: Treats antibiotics as directly causing resistance mutations rather than selecting bacteria that already have resistance.
B: Confuses reduced selection with blocked inheritance; resistant bacteria can still pass resistance to offspring.
C: Assumes resistance disappears without antibiotics; reduced use does not itself remove resistance.
Remember: antibiotics select among bacterial variants; they do not direct bacteria to become resistant.