AP BIOLOGY

Detailed explanation-1: -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-2: -Why are plasmids sometimes given an antibiotic resistance gene? So that scientists can make antibiotic resistant bacteria and make more money for pharmaceutical companies.

Detailed explanation-3: -A plasmid typically contains an antibiotic resistance gene, which allows bacteria to survive in the presence of a specific antibiotic. Thus, bacteria that took up the plasmid can be selected on nutrient plates containing the antibiotic.

Detailed explanation-4: -Bacteria with a plasmid are antibiotic-resistant, and each one will form a colony. Colonies with the right plasmid can be grown to make large cultures of identical bacteria, which are used to produce plasmid or make protein.