Genetic modification

Genetic modification changes an organism’s genetic material by removing, changing or inserting individual genes. Genes contain instructions for making proteins. Changing the genes an organism has can therefore change the proteins it makes, alter its characteristics or enable it to produce a desired protein.

Genetic modification of bacteria

A human gene can be inserted into a bacterium. The bacterium can then use the gene’s instructions to produce the human protein. For example, bacteria can be genetically modified to produce human insulin.

Genetic modification of crop plants

Genes can be inserted into crop plants to give them useful characteristics. For example, a gene may make a crop resistant to a herbicide, so the crop can survive when that herbicide is applied. Another gene may give a crop resistance to insect pests, reducing the damage they cause.

Genes can also be inserted to improve a crop’s nutritional qualities, such as by increasing the amount of a useful nutrient it produces.

Benefits and risks of GM crops

Genetically modified (GM) crops have had their genes modified to give them desired characteristics. These characteristics can help farmers reduce crop losses or improve the quantity and quality of the food produced.

Benefits of GM crops

A GM crop may be made resistant to disease or insect attack. If fewer plants are damaged or lost, more of the crop can be harvested. A crop may also be made resistant to a herbicide, allowing the herbicide to be used against unwanted plants without damaging the crop.

Other modifications can produce larger or better-quality fruits. By reducing losses or improving production, GM crops generally give increased yields: more crop is harvested from the same area of land.

Risks and concerns about GM crops

Changes in how a GM crop is grown can affect organisms beyond the crop itself. For example, herbicide use may reduce wild flower populations in and around fields. Insects that depend on those plants for food or habitat may then also be affected.

Some people also question whether the effects of eating GM crops on human health have been fully explored. A concern about a possible effect, however, does not by itself establish that harm occurs.

Medical applications of genetic engineering

Genetic engineering can give cells a gene that provides instructions for making a useful substance. A gene can be cut out of the chromosomes of one organism and transferred into cells of another organism. The receiving cells can then use the gene to make the substance.

Producing human insulin

A human gene for insulin can be introduced into bacterial cells. The bacteria use the gene’s instructions to produce human insulin, which can be collected and used to treat diabetes. This allows a medicine needed by patients to be produced using genetically modified organisms.

Medicines made this way must be assessed for safety and purity before use. For example, the insulin preparation must be checked for harmful contaminants as well as whether it is safe for patients.

Investigating inherited disorders

An inherited disorder can result from a gene that does not provide functional instructions for making a protein. Researchers are investigating whether introducing a functional gene into affected cells could allow those cells to make the protein. This could address an underlying genetic cause of a disorder, rather than only treating its effects.

Changing human cells can have unintended effects, and the long-term outcomes may be uncertain. Some people also have ethical objections to modifying human cells. These risks and concerns must be considered alongside the potential benefits.