The human insulin gene contains a number of sequences that are removed in the processing of the primary RNA transcript. In spite of the fact that bacterial cells cannot excise these sequences from primary RNA transcripts, explain how a gene like this can be cloned into a bacterial cell and produce insulin.
A) Bacterial cells can be easily modified so that they are able to excise introns.
B) Plasmids containing an insulin gene that is derived from cDNA, rather than genomic DNA, would be void of introns. Therefore, intron processing would not be necessary.
C) Plasmids containing insulin genes derived from genomic DNA would be void of introns. Therefore, intron processing would not be necessary.
D) Plasmids containing insulin genes derived from genomic DNA would contain introns, but because the intron sequences are relatively short, the newly synthesized insulin would still likely be functional.

The exons are the coding sequence whereas introns are non coding sequence of the genome. The eukaryotes genome are interrupted with introns wheres prokaryotes lacks the intron in their structure.

The insulin hormone is necessary for the miantenance of the blood sugar level. The insulin gene present in the plasmid should be from the cDNA as cDNA is produced from the mRNA and do not contain any intron in its structure. No splicing is required in the cDNA.

Thus, the correct answer is option (B).