Please help me help in bio i'm failing too!!!What is the amino acid sequence of gene on the cell DNA?

in that recombinant chunk of DNA that you are inserting into the bacteria, you put the gene for ampicillin resistance (the typical one used, but you could probably use any).
when you are growing up the bacteria in the dishes, you split the dishes up into bacteria without the new plasmid inserted and bacteria with the new plasmid. you treat the dishes with ampicillin after the bacteria are established and starting to grow. after a short time (a day or so), the bacteria without the new plasmid should die while the ones with the new plasmid will live (because they are RESISTANT to ampicillin treatment).

if the ampicillin gene is on the same recombinant plasmid as whatever substance you are trying to produce commercially, then all you have to do is stick the plasmid into the bacteria and they take care of the rest.

i don't understand your last question...so sorry can't help with that one. (i think you want to know what the a.a sequence of the plasmid dna is? well since you made the recombinant plasmid, you'd already know the dna code and so could derive the a.a. sequence from there using the codon table)

good luck!