Question

In 1943, drug companies began mass-producing penicillin. At that time, it was a medical miracle and was used as a remedy for infected wounds, pneumonia, and other bacterial diseases. Just four years later, however, it was no longer effective on the same diseases that it had previously been able to cure. What happened?

Answer 1

The diseases found new host cells within the body.
The diseases were no longer caused by bacteria.
Some of the bacteria mutated to become resistant to penicillin.
Some of the bacteria were able to hide from the penicillin in the body.

Answer 2

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