Question

Which of the following best explains the change in the frequency of penicillin resistance in S. aureus from 1940 to 2010?A) S. aureus that were resistant to penicillin evolved to use penicillin as an energy source that nonresident strains could not use. B) S. aureus that were resistant to penicillin developed a mutualistic relationship with humans, while the nonresident strains did not.C) S. aureus that were resistant to penicillin evolved to produce more quickly than nonresident strains. D) S. aureus that were resistant to penicillin survived and reproduced in the presence of the antibiotic, while nonresident strains did not.

Answer 1

The alternative that best explains the change in the frequency of penicillin resistence in S. aureus is:

D) S. aureus that were resistant to penicillin survived and reproduced in the presence of the antibiotic, while nonresident strains did not.

The bacteria strain resistance to a antibiotic melecule is a case of the ability to defeat the drug by the process of adaptation to the substance. When a organisms is exposed to a antibiotic for a long time it will adapt to survive, since artificial selection will take place by the pressure of the drug in the environment, being the bacteria that can survive and reproduce able to make everytime more resistant offspring.