Well, artificially constructing biological DNA could lead to the alteration of abnormal, or malice genes. In other words, if you had a gene for down syndrome, the genetically modified anti-biotic could mutate the malice chromosome into something less harmfull. Today, scientist use plasmids to construct artificial immunities such as; the flu shot(or a genetically altered version of a passive flu virus) or Cloning(remember the lamb on the news?). Also artificially constructing genes could lead to solution to world hunger: Clone the same cabbage plant a hundred times and you could feed an entire community with just one gene.