Genetically Modified Organisms (GMO):
When a gene from one organism is purposely moved to improve
or change another organism in a laboratory, the result is a genetically
modified organism (GMO). It is also sometimes called "transgenic"
for transfer of genes.
There are different ways of moving genes to produce desirable
traits. For both plants and animals, one of the more traditional ways
is through selective breeding. For example, a plant with a desired trait
is chosen and bred to produce more plants with the desirable trait. More
recently with the advancement of technology is another technique. This
technique is applied in the laboratory where genes that express the desired
trait is physically moved or added to a new plant to enhance the trait
in that plant. Plants produced with this technology are transgenic. Often,
this process is performed on crops to produce insect or herbicide resistant
plants, they are referred to as Genetically Modified Crops (GM crops).

Results of insect infestation on Bt (right) and non-Bt (left) cotton
bolls. Source: USDA
Other GM products
Genetically engineered products are not new. Insulin
used in medicine is an example of genetic engineering; the insulin gene
from the intestines of pigs is inserted into bacteria. The bacterium grows
and produces insulin; this insulin is then purified and used for medical
purposes. Thyroid hormones, until recently was derived only from animals,
now the hormone can be cultured from bacteria. Other genetically engineered
products include the chemical Aspartame used in sugar free foods, and
the drug hepatitis B vaccine.
Engineering vs breeding
So why use molecular biology over traditional breeding?
With traditional breeding, plants often exchange large, unregulated chunks
of their genomes. This can lead to both useful and unwanted traits in
the offspring. Sometimes these unwanted traits can be unsafe. One example
would be potato varieties made using conventional plant breeding that
inadvertently produced excessive levels of naturally occuring glycoalkoloids.
These glycoalkoloids cause cause gastrointestinal, circulatory, neurological
and dermatological problems associated with alkaloid poisoning.
Breeders sometimes have to cross many plants over multiple
generations to produce the desired trait. GM techniques allow new traits
to be introduced one at a time without complications from extra genes
and extensive crossbreeding. GM techniques also allow traits from different
organisms to be applied, such as pest resistance.
Types of GM plants
Most GM crops grown today have been developed to resist
certain insect pests. There are GM plants being developed today to produce
specific vitamins, resist plant viruses and even produce products for
medical uses. Countries that grow GM crops include; Argentina, Australia,
Canada, China, Germany, India, Indonesia, Mexico, Portugal, South Africa,
Spain, United States, Ukraine, and many more.
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