Human insulin is produced in large scale by inserting the gene responsible for the production of insulin from humans into the genome of a ___.
bacteria
The gene responsible for insulin secretion in humans is inserted into the genome of a bacterial cell to get a combined genome. As a result, these bacteria produce functional human insulin.
Animals like pigs and cows can also be used to produce human insulin through genetic engineering. But it is not suitable for large scale production of insulin since its expense is more.