In the process of genetic engineering a gene from one organism is transferred to another organism. The organism that receives the gene is called a genetically modified (GM) organism.
If the gene has come from a different species the organism is described as transgenic. Two examples of transgenic organisms are - bacteria and plants.
Bacteria can be genetically modified by giving them the gene that has the instructions for making the human protein insulin.
Plants can be genetically modified to have genes that give them herbicide resistance or make them toxic to insects. We can also genetically modify plants to increase their productivity.
The video below looks at work to genetically modify rice plants, to improve their photosynthesis.
In this process different organisms are genetically modified so that they can produce medically useful substances such as drugs and vaccines.
Pharming is used to genetically modify organisms because there is an increasing global demand for products such as vaccines which can be used to treat dieases such as cystic fibrosis and non-Hodgkin's lymphoma.