Question

Which of the following helps to explain why antibiotic resistance can evolve especially quickly?

1) bacteria reproduce quickly
2) bacteria can acquire genes from other bacteria
3) antibiotics provide strong selection pressure
4) all are correct

Answer 1

Antibiotic resistance evolves rapidly due to bacteria's quick reproduction, their ability to exchange genes, and the strong selection pressure exerted by the use of antibiotics. These factors result in natural selection favoring resistant bacteria, thus promoting the spread of resistance genes in bacterial populations.

Step-by-step explanation:

The quick evolution of antibiotic resistance in bacteria can especially be attributed to three primary factors:

1. Bacteria reproduce quickly, leading to a short generation time.
2. Bacteria can acquire genes from other bacteria through mechanisms like genetic recombination and lateral gene transfer.
3. The use of antibiotics provides a strong selection pressure wherein the resistant bacteria are more likely to survive and reproduce.

All of these points contribute to the evolution of antibiotic resistance, which is a prime example of natural selection. Resistant bacteria thrive because the genes for resistance are already present and usually at a low frequency. However, when antibiotics are applied, these genes become advantageous, allowing the resistant bacteria to survive and multiply, leading to a higher frequency of resistant genes in the population. The incorrect and excessive use of antibiotics only exacerbates the problem by increasing the selective pressure on bacteria to evolve resistance.