Question

How do scientists insert and remove single genes from DNA?

Answer 1

Scientists use recombinant DNA technology, which allows them to combine the DNA of different species. Restriction enzymes are used to cut open a plasmid, small circles of DNA in bacterial cells, and the same enzyme is used to cut the desired gene out of the chromosome. This makes two matching cuts, and when the gene and plasmid are combined, they form a temporary bond. Another enzyme, DNA ligase, is used to create a permanent seal.

Source: http://library.thinkquest.org/04apr/00217/en/products/recdna/about.html