7. A student gets ill and misses school to see the doctor. After a brief checkup, the doctor says
that it appears to be a bacterial infection and prescribes an antibiotic (antibiotic A). After
taking this antibiotic for two weeks, it does not work and a culture shows that the bacterial
infection is of a type that requires a different antibiotic (antibiotic B). Antibiotic B does work
after taking it for two weeks. Why could taking the wrong antibiotic (antibiotic A) at the
beginning be a problem?
A. The bacteria making the student ill will evolve resistance to antibiotic A.
B. Antibiotic B will compete with antibiotic A, making it more likely for bacteria to evolve
antibiotic resistance.
C. Antibiotic B will not work again for the student because it caused the student's immune
system to build up antibodies.
D. Certain bacterial populations, that are not causing the illness in the student, will be more
likely to evolve resistance to antibiotic A.