Which way of evolution cases the FQ antibiotic resistance in the Evolution- HighSchool Stem Case Gizmos?Gene Flow, Genetic Drift, or Natural Selection?
The correct Answer and Explanation is:
In the Evolution – HighSchool STEM Case Gizmos, natural selection is the primary evolutionary mechanism that causes fluoroquinolone (FQ) antibiotic resistance.
Explanation:
Natural selection is a process where organisms with traits that confer a survival or reproductive advantage in a given environment are more likely to survive, reproduce, and pass on those advantageous traits to their offspring. In the context of antibiotic resistance, bacteria with genetic mutations that make them resistant to fluoroquinolone antibiotics will have a selective advantage in an environment where this antibiotic is present.
When fluoroquinolones are used to treat bacterial infections, they kill or inhibit the growth of susceptible bacteria. However, a small subset of the bacterial population may carry mutations in their DNA that provide resistance to these drugs. These resistant bacteria survive the antibiotic treatment and continue to multiply, while the non-resistant bacteria die off. Over time, the population becomes dominated by resistant strains due to the selective pressure exerted by the antibiotic. This is an example of directional selection, where the environment (presence of the antibiotic) favors organisms with a particular trait (antibiotic resistance).
On the other hand, gene flow refers to the transfer of genetic material between populations, which might introduce new traits but is not directly responsible for the spread of antibiotic resistance unless resistant genes are being transferred. Genetic drift is the random fluctuation of allele frequencies in small populations, but it is more likely to cause random changes in traits rather than the systematic increase in antibiotic resistance observed with natural selection.
In conclusion, natural selection drives the development of fluoroquinolone resistance in bacteria by favoring the survival and reproduction of resistant strains in the presence of the antibiotic.