Answer: The recessive allele is responsible for resistance of the bacteria to the antibiotic.
Explanation:
Hardy-Weinberg's law establishes that in a large population, in which mating occurs at random and which is not subject to mutation, selection or migration; gene and genotypic frequencies remain constant from one generation to the next.
In this example, the repeated exposure to an antibiotic, causes the frequency of recessive alleles to increase. This is beacause the recessive alleles are responsible fot the resistance to the antibiotic. Once the antibiotic is used, there is a "selective pressure" on bacteria because it will be the strains that acquire resistance that will be able to survive and reproduce. Before that, the recessive alleles were not needed because there was no antibiotic present
