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GENETICALLY ENGINEERED FOOD …
What are genetically-modified foods?
The term GM foods or GMOs (genetically-modified organisms) is used to refer to crop plants
created for human or animal consumption using the latest molecular biology techniques.
These plants have been modified in the laboratory to enhance desired traits such as increased
resistance to herbicides or improved nutritional content. The enhancement of desired traits
has traditionally been undertaken through breeding, but conventional plant breeding
methods can be very time consuming and are often not very accurate. Genetic engineering,
on the other hand, can create plants with the exact desired trait very rapidly and with great
accuracy. For example, plant geneticists can isolate a gene responsible for drought tolerance
and insert that gene into a different plant. The new genetically-modified plant will gain
drought tolerance as well. Not only can genes be transferred from one plant to another, but
genes from non-plant organisms also can be used. The best known example of this is the use
of B.t. genes in corn and other crops. B.t. (Bacillus thuringiensis) is a bacterium which
produces proteins that are lethal to insects – the plant produces its own pesticides against
insects.
What are some of the advantages of GM foods?
Ensuring an adequate food supply for the population is going to be a major challenge in the
years to come. GM foods promise to meet this need in a number of ways:

Pest resistance: But, the consumers do not wish to eat food that has been treated with
pesticides because of potential health hazards, and agricultural wastes from the use of
pesticides and fertilizers can poison the water and can harm the environment.

Herbicide tolerance: Weeds can be removed by physical means such as tilling, but
farmers often spray different herbicides (weed-killer) to destroy weeds.

Disease resistance: There are many viruses, fungi and bacteria that cause plant diseases.
Plant biologists are working to create plants with genetically-engineered resistance to
these diseases.

Cold tolerance: Frost can destroy sensitive seedlings. With the antifreeze gene, plants are
able to tolerate cold temperatures that would normally kill unmodified seedlings.
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
Drought tolerance: As the world population grows and more land is used for housing
instead of food production, farmers will need to grow crops in locations previously
unsuited for plant cultivation.

Nutrition: Malnutrition is common in third world countries where people rely on a single
crop such as rice. Rice does not contain adequate amounts of all necessary nutrients to
prevent malnutrition. Rice could be genetically engineered to contain additional vitamins
and minerals.
What are some of the criticisms against GM foods?
Most concerns about GM foods fall into three categories: environmental hazards, human
health risks and economic concerns:
Environmental hazards

Unintended harm to other organisms

Reduced effectiveness of pesticides: insects may become resistant to B.t. or other crops
that have been genetically-modified to produce their own pesticides.

Gene transfer to non-target species: crop plants engineered for herbicide tolerance and
weeds may cross-breed - these "super weeds" would then be herbicide tolerant as well.
Human health risks

Allergies

Unknown effects on human health: introducing foreign genes into food plants may have
an unexpected and negative impact on human health, but scientists believe that GM
foods do not present a risk to human health.
Economic concerns
Consumers are worried that patenting these new plant varieties will raise the price of seeds
so high that small farmers and third world countries will not be able to afford seeds for GM
crops, thus widening the gap between the wealthy and the poor.
How are GM foods labelled?
Labelling of GM foods is not obligatory nowadays. Agribusiness industries believe that
labelling should be voluntary and influenced by the demands of the free market.
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If the food production industry is required to label GM foods, factories will need to construct
two separate processing streams and monitor the production lines accordingly. Farmers
must be able to keep GM crops and non-GM crops from mixing during planting, harvesting
and shipping. It is almost assured that industry will pass along these additional costs to
consumers in the form of higher prices.
Conclusion
Genetically-modified foods have the potential to solve many of the world's hunger and
malnutrition problems, and to help protect and preserve the environment by increasing yield
and reducing reliance upon chemical pesticides and herbicides. Yet there are many
challenges ahead for governments, especially in the areas of safety testing, regulation,
international policy and food labelling.
EXERCISES
1. Fill in the missing words or phrases.
1. GM foods have been _______________ in a lab to enhance certain _______________, such
as pest resistance, herbicide tolerance, disease resistance, improved _______________
content, etc. In _______________ agriculture these traits are achieved through
_______________.
2. There are many _______________, _______________ and bacteria which cause plant
diseases.
3. Frost can kill seedlings, but antifreeze gene can improve GM plants’ _______________
tolerance.
4. _______________ is often a big problem of the third world countries, because people
don’t eat a variety of foods.
5. Most concerns about GM foods fall into three categories: _______________,
_______________ and _______________.
6. Food industry is not required by law to _______________ GM foods, and it would result
in higher _______________ for the consumer.
7. The problem for farmers would also be how to keep GM crops and non-GM crops from
mixing during _______________, _______________ and _______________.
2. The advantages of GMOs outweigh the disadvantages. Do you agree?
Vir: text adapted from: http://www.csa.com/discoveryguides/gmfood/overview.php