scientists took a clue from naturally occurring dna mutations and began to use bacteria plasmids to alter genes in other organisms. first the simple, circular bacterial plasmid, that contains a small amount of dna, is isolated. a piece of dna with a gene of interest from another organism, plant or animal, is spliced into the plasmid dna. scientists place the transformed plasmid into a bacteria culture and the bacterial cells take up the altered plasmid. the new, recombinant bacterial cells multiply, now with the original plasmid containing the gene scientists were interested in cloning, for use in genetic engineering.  in this case, scientists have copied a type of naturally occurring genetic mutation calleda)deletion. b)reversion. c)insertion. d)crossing over.