Genetic Modification (or Genetic Engineering)
- Genetic modification is the process of taking a gene from one species and putting the gene into another species.
- Transgenic organism is an organism that has undergone genetic modification and has had genetic material transferred from a different species.
- Genetic engineering is beneficial because it can produce organisms that have desired characteristics.
- Genetically modified bacteria can produce large amounts of human insulin to treat diabetes.
- Plants can be genetically modified to have desired characteristics, such as disease resistance, larger fruits or high levels of nutrition.
Important terms to know for IGCSE Biology:
- Restriction enzymes cut DNA at specific sites. You can think of restriction enzymes as scissors that can cut DNA!
- Ligase is an enzyme that joins pieces of DNA together. Ligases are like glues that glue DNA pieces.
- Vectors are DNA molecules that carry DNA from another species into a cell. Plasmids and viruses are commonly used as vectors for genetic engineering.
- When a gene with desired characteristics is inserted into the vector, we call it a recombinant DNA.
How Bacteria is Genetically Modified to Produce Insulin
- The gene that is responsible for controlling the formation of insulin is cut out from human chromosome using restriction enzyme.
- A plasmid is isolated from a bacteria, and the plasmid is cut with the same restriction enzyme that was used to cut the human chromosome.
- The gene that was cut out from human chromosome is inserted into the plasmid using ligase. The plasmid now contains the insulin gene.
- The plasmid is inserted back to the bacteria. Plasmid is the vector that carries human insulin gene into bacteria.
- When this transgenic bacteria is grown in a fermenter, it will reproduce rapidly, and a large amount of insulin will be produced.