Genetic engineering.

Genetic Engineering a gene is cut out of a human chromosome using enzymes a DNA plasmid is taken out of a bacterium and cut open using enzymes the human insulin gene and the plasmid are mixed together. the human insulin gene and the plasmid are stuck together to make a new plasmid. the new plasmid with the human insulin gene is put back into a bacterium. the bacterium has been genetically modified. the bacterium will now make human insulin.