AP BIOLOGY

Detailed explanation-1: -Ampicillin is an antibiotic and works by preventing E. coli from constructing cell walls, thereby killing the bacteria. When the ampicillin-resistance gene is present, it directs the production of an enzyme that blocks the action of the ampicillin, and the bacteria are able to survive.

Detailed explanation-2: -If a recombinant DNA bearing gene for resistance to antibiotic ampicillin is transferred to E. coli cells, the host cells become transformed into ampicillin-resistant cells.

Detailed explanation-3: -Adding an antibiotic resistance gene to the plasmid solves both problems at once – it allows a scientist to easily detect plasmid-containing bacteria when the cells are grown on selective media, and provides those bacteria with a pressure to keep your plasmid.

Detailed explanation-4: -b-lactamase enzyme is the product of the bla gene (genes are typically lower case and italicized) If a plasmid contains the bla gene, it will confer resistance to ampicillin to the host E. coli.