Recombinant DNA technology involves the creation of new combinations of DNA sequences that are not found in nature. This technology can be used to create a wide range of products, including vaccines and genetically modified plants.
(i) A vaccine: Recombinant DNA technology can be used to create vaccines by inserting a gene for a disease-causing antigen into a harmless microbe or virus, which can then be used to trigger an immune response. For example, the Hepatitis B vaccine is produced using recombinant DNA technology. The gene for the Hepatitis B surface antigen is inserted into yeast cells, which are then used to produce large amounts of the antigen. This antigen is then purified and used as a vaccine to protect against Hepatitis B.
(ii) A plant with delayed fruit ripening: Recombinant DNA technology can be used to modify plant genes, allowing for the production of plants with desirable traits. For example, the FLAVR SAVR tomato was created using recombinant DNA technology. The gene responsible for the enzyme polygalacturonase (PG), which causes the breakdown of cell walls and leads to fruit softening, was modified using recombinant DNA technology. This modification led to delayed fruit ripening and allowed for longer shelf life. The resulting plant was then used to create tomatoes that had a longer shelf life, reducing waste and increasing availability.