The introduction of antibiotics such as penicillin several years ago was immediately effective in combating infections caused by Staphylococcus. In 1958, however, there were several outbreaks of staphylococcal infections. People with the infections did not respond to treatment with any of the antibiotics and there was a large number of deaths. The best explanation for this situation is that
(A) the bacteria reproduced in hosts that were not contaminated with antibiotics
(B) the bacteria from other hosts such as birds, cats, and dogs migrated into human hosts
(C) the bacteria exposed to nonlethal doses of antibiotics quickly learned to avoid them
(D) each generation of bacteria acquired the ability to use antibiotics as nutrients
(E) antibiotic-resistant bacteria survived and multiplied, and these were the forms causing the infections
Answer: E
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AP Biology
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