Practise AP Biology 7.3.A questions by explaining how humans select organisms with desired heritable traits and thereby change diversity within populations.
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
(i) Describe the process of selection used in this experiment.