Patient A and Patient B are infected with a harmful strain of bacteria.
For treatment of the infection, both patients are prescribed an antibiotic that will specifically eliminate the harmful bacteria.

The antibiotic is to be taken three times a day over the course of one week until all the pills are finished.
Patient A takes the antibiotic as prescribed.

Patient B, however, starts feeling better after 3 days and decides to stop taking the antibiotic pills.
Patient A now is completely clear of the harmful bacteria.

Patient B experiences re-infection, and the antibiotic is no longer effective against the harmful strain.
How are bacteria able to divide and grow in a host?
infection followed by binary fission
infection followed by mitosis
infection followed by meiosis
infection followed by any form of cell division
What was the prescribed antibiotic supposed to do for these patients?
directly enhance the growth of harmless bacteria
directly hinder the activity of both harmless and harmful bacteria
specifically hinder activity of harmful bacteria to destroy and eliminate them
make host cells stronger so that they can clear out harmful bacteria
Why were the harmful bacteria completely eliminated in Patient A?
Patient A probably was given a stronger dose of the antibiotic.
Consistent exposure to the antibiotic over time caused harmful bacteria to be eliminated as harmless bacteria thrived.
The harmless bacteria were stronger than the harmful bacteria.
Patient A had stronger host cells, which specifically defended against the harmful bacteria.
Why are harmful bacteria still present in Patient B?
In Patient B, many of the harmless bacteria were converted into harmful bacteria.
The antibiotic enhanced the growth of harmful bacteria in Patient B.
Because Patient B failed to take every dose of the antibiotic, many of the harmful bacteria remained alive.
There probably were more harmful bacteria in Patient B than in Patient A. Treatment with antibiotic was pointless.
Why won’t the same antibiotic work for Patient B when the harmful bacterial infection reoccurs?
The second time around, the harmless bacteria shield the harmful bacteria.
Generally, an antibiotic only can be prescribed once. The second time is always ineffective.
Exposure to the antibiotic the first time around allowed harmful, antibiotic-resistant bacteria to produce new populations of antibiotic-resistant bacteria.
Patient B’s harmful bacteria probably were not capable of responding to the antibiotic in the first place.