Exemplar Problems

Question:

Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.

Answer:

• Antibiotic resistance in bacteria can be explained using Darwinian selection theory. When antibiotics are introduced, they act as selective pressures on bacterial populations.

  • Within a bacterial population, there is genetic variation, and some bacteria may have mutations that make them resistant to the antibiotic.

  • When the antibiotic is used, susceptible bacteria are killed, but resistant bacteria survive and reproduce.

  • Over time, the resistant bacteria become more prevalent in the population, as they have a reproductive advantage.

  • This is an example of natural selection, where the environment (presence of antibiotics) selects for the survival and reproduction of individuals with advantageous traits (antibiotic resistance). The resistant bacteria pass on their resistance genes to offspring, leading to the spread of resistance in the population.