Question

a scientist constructs a recombinant bacterial plasmid that contains a gene conferring resistance to the antibiotic ampicillin (amp). the scientist transforms cultures of e. coli bacteria with the recombinant plasmid, then incubates the cultures overnight on plates containing media without ampicillin (amp - ) and with ampicillin (amp + ). assuming the transformation protocol was successful, which of the following best predicts the bacterial growth pattern expected after the incubation period? = no bacterial growth = some bacterial growth = high bacterial growth choose 1 answer: a amp - amp + b amp - amp + c amp - amp + d amp - amp +

Explanation:

1. Understand the Experiment: The scientist transformed E. coli with a plasmid containing an ampicillin - resistance gene. Then, the bacteria were plated on amp - (no ampicillin) and amp+(with ampicillin) media.
2. Growth on amp - Media: On the medium without ampicillin (amp - ), both the transformed (with the plasmid) and non - transformed (if any) E. coli can grow. Since the transformation is successful, most of the bacteria should be able to grow well, so we expect high bacterial growth (the “High bacterial growth” symbol) on the amp - plate.
3. Growth on amp + Media: On the medium with ampicillin (amp + ), only the bacteria that have taken up the recombinant plasmid (and thus have the ampicillin - resistance gene) can grow. Since not all bacteria may have taken up the plasmid (transformation efficiency is not 100%), we expect some bacterial growth (the “Some bacterial growth” symbol) on the amp + plate.
4. Match with Options: Looking at the options, option C has high growth on amp - and some growth on amp +, which matches our prediction.

Answer:

C. amp - (High bacterial growth), amp + (Some bacterial growth)