In preparation for cloning a gene into a plasmid, you haveobtained a 3kb plasmid vector containing two selectable markergenes. One selectable marker renders E. coliresistant to the antibiotic ampicillin. The other selectablemarker, which also contains the multiple cloning site, rendersE. coli resistant to the antibiotic tetracycline. Ifyou successfully clone a foreign piece of DNA into this plasmid atthe multiple cloning site and transform E. coli cells withthe recombinant plasmid, indicate the answer to the followingquestions.

a. How would you select against E. coli cells that havenot been transformed with a plasmid?

b. Which antibiotic(s), if any, will cells be resistant to ifthey have obtained a plasmid that does not contain foreign DNA?

c. Which antibiotic(s), if any, will cells be resistant to ifthey have obtained a plasmid containing inserted foreign DNA?

d. How would you distinguish recombinant and non-recombinant plasmids by agarose gel electrophoresis.