Final answer:
Bacteria with the recombinant plasmid can be identified by growing them on a plate with ampicillin and a substance that changes color when exposed to the enzyme produced by the lacZ gene.
Step-by-step explanation:
To find the bacteria with the recombinant plasmid, the bacteria are grown on a plate with the antibiotic ampicillin and a substance that changes color when exposed to the enzyme produced by the lacZ gene. The ampicillin will kill any bacteria that did not take up a plasmid. The color of the substance will not change when the gene for lacZ contains the foreign DNA insert. These are the bacteria with the recombinant plasmid that we want to grow.