AP Biology 7.3 Artificial Selection Questions

A sample of a culture of E. coli is plated onto two LB agar plates: plate 1 containing LB agar and no antibiotic (LB) and plate 2 containing LB agar with 50 micrograms/mL of the antibiotic ampicillin (LB + amp).

Both plates are incubated at 37°C for 24 hours. Bacteria from plate 1 are plated onto two more plates: one with LB agar (plate 3) and the other containing LB agar with 50 micrograms/mL of the antibiotic ampicillin (plate 4). Bacteria from plate 2 are plated onto plate 5 (containing LB agar) and plate 6 (containing LB agar with 250 micrograms/mL of the antibiotic ampicillin). This second round of plates are all incubated at 37°C for 24 hours. A diagram of the experiment is shown below.

Part A

Describe the process of selection used in this experiment.