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Researchers have noted that chloramphenicol (a commonly used antibiotic) is becoming less effective in treating typhoid fever. The best explanation for this observation would be selection:
ANS: for chloramphenicol resistance in populations of S typhi.
(note: according to the passage, S. Typhi is the causative agent of typhoid fever.)
Can someone please explain to me the rationale behind the answer, noteably, the difference between selecting for/against? What exactly does this mean? Thank you!
ANS: for chloramphenicol resistance in populations of S typhi.
(note: according to the passage, S. Typhi is the causative agent of typhoid fever.)
Can someone please explain to me the rationale behind the answer, noteably, the difference between selecting for/against? What exactly does this mean? Thank you!