Question

Below are 6 steps involved in the evolution of Ab resistance, listed in a scrambled order. Organize the steps in the order in which they actually occur

1. An advantageous mutation occurs that does not influence Ab-resistance, but increases growth rate.

2. Antibiotics are introduced into the environment.

3. A deleterious mutation occurs in a single cell that confers antibiotic resistance but compromises growth rate.

4. The individual cell with the Ab-resistant allele survives and reproduces slowly.

5. The antibiotic is more-or-less obsolete (useless, ineffective).

6. Selection favors compensatory mutations in the Ab-resistant population to favor the evolution of higher growth rates.

Answer 1

1. Antibiotics are introduced into the environment.

2. A deleterious mutation occurs in a single cell that confers antibiotic resistance but compromises growth rate.

3. The individual cell with the Ab-resistant allele survives and reproduces slowly.

4. An advantageous mutation occurs that does not influence Ab-resistance but increases growth rate.

5. Selection favors compensatory mutations in the Ab-resistant population to favor the evolution of higher growth rates.

6. The antibiotic is more-or-less obsolete (useless, ineffective).