Question

How does a human insulin gene become part of a bacterium's plasmid?

Answer 1

1. Scientists remove plasmids, small rings of DNA, from bacterial cells.
2. An enzyme cuts open the plasmid DNA. The same enzyme removes the human insulin gene from its chromosome.
3. The human insulin gene attaches the open ends of the plasmid to form a closed ring.
4. Some bacterial cells take up the plasmids that have the insulin gene and reproduce

Here is a diagram if it will help better
http://faculty.utrgv.edu/luis.materon/3401/mainimages/insulin.gif