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triteritzyBiotechnology

Dec 14, 2012 (4 years and 7 months ago)

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Genetically Modified Foods

A presentation by
Imaiya

R,
Devang

A,
Curan

K, Bay
Z, and
Gurvir

K



Genetically Modified Foods refer to crops that have been
genetically altered to provide new and/or enhanced characteristics



It is an effective, yet controversial method of agriculture



Introduction

What are they?


The concept behind GMF’s is not a new one


Farmers have been using a basic method known as “mutagenesis”
for years. Like breeding dogs, farmers used artificial selection to
grow crops with
desried

qualities


Introduction

Development



This process, while correct, was
uneffecient


Genetic engineering techniques were introduced
around 1994 to make the process quicker and more
exact




The first commercially grown genetically modified
food crop was a tomato; it was modified to ripen
without softening


Nowadays, products that are most commonly altered
using genetics are: soybean, corn, and sugar canes



The major difference between organic and GMF’s are the increase
in probability for the food in question to be toxic


This means that GMFs’ molecular structure is greatly
compromised



GMF’s also tend to produce their own form of pesticide



Chemical Aspect



However, the differences in molecular structure
parallel the differences found through NATURAL
genetic mutations (mutagenesis, etc.)


The biology behind GMF’s is basically they process from which
GMF’s are created. This process, which is known as genetic
engineering, is where one or more gene(s) are taken out,
essentially isolated from the DNA, and then inserted into the DNA
if the other organism. Special enzymes, called
restriction
endonucleases
, act as scissors to cut out a desired
gene.There

is a
variety of the number of enzymes that cut, in different places, so
the enzyme used is dependent on the sequence of the DNA strand
surround a specific gene.



Biological Aspect


Much controversy exists concerning whether GM foods are viable.
Such segregation is apparent by the ‘acceptance’ of segregated
schools by specific countries:




U.S.A: 44 Approvals of GM foods


Canada: 42 Approval of GM foods


UK: 19 approval of GM foods; only 5 on the market



Advantages and Disadvantages

The Controversy


Crop losses due to insect pests can cause a huge financial loss for
farmers and also cause starvation in developing countries.


To combat insects, farmers have to use large quantities of
pesticides which affects sales since consumers don’t want to eat
foods that have been treated with pesticides.


Also, excessive use of pesticides can cause run
-
off waste which
can poison the water and cause harm to an ecosystem.


But growing GM foods like B.T. corn significantly reduces the
amount of pesticides needed as these crops have their own toxin
which makes them less susceptible to insect pests.



Advantages

Pest Resistance


These Foods are modified to become resilient to pest infestations
therefore, saving money (although GM seeds are more expensive) and
aiding the environment because pesticides and chemicals are therefore,
unnecessary to maintain the health of crops.




Removing weed or killing weed is a time
-
consuming and an
expensive process for farmers as they have to use large quantities
of different herbicides (weed
-
killer) to destroy weed.


But they have to be careful so that the herbicide does not affect
their crop.


Thus plants that are genetically
-
engineered to be resistant to
powerful herbicides could help reduce the amount of herbicides
needed while not harm the crop.


Ex: Monsanto (chemical company


now also develops and
markets GMF technology) has genetically modified soybeans to be
not affected by their herbicide product ‘
Roundup’
.




Advantages

Herbicide Tolerance


Now farmers can use these soybeans which only require one application
of weed
-
killer instead of multiple applications, reducing production cost
and reducing run
-
off waste.




Ex: Monsanto (chemical company


now also develops and markets GMF
technology) has genetically modified soybeans to be not affected by their herbicide
product ‘
Roundup’
.


Sometimes farmers lose their crops to many viruses, fungi and
bacteria that cause plant diseases.


Plant biologists are working to create genetically modified plants
that are resistant to these diseases.




Advantages

Disease Resistance


Unexpected frost can kill seedlings which results in crop familiar.


An antifreeze gene from cold water fish has been introduced into
plants such as tobacco and potato to withstand the cold.


Now these plants are able to survive the colder temperature that
normally would kill unmodified seedlings.




Advantages

Climate Conditions


As world population grows, it will become harder for farmers to find ideal soil to
grow crops. So farmers need to grow crops in locations that were previously
unsuited for plant cultivation.


Creating plants that can withstand long periods of drought or high salt content in
soil/groundwater will help farmers to grow crops in previously unsuited places.


Foods can be genetically engineered to prosper in climate conditions that may
otherwise be detrimental to the growth of the plant.


This can aid people in areas where regular crops will not prosper.




=

Less fertile soil

Future Increase in Population


Malnutrition is an issue in countries where people rely on one
type of crop for their nutrition; crops such as rice.


Rice doesn’t contain all necessary nutrients, hence causing
deficiencies.


Ex: blindness due to lack of vitamin A is a common problem in third
world countries. So researchers at Swiss Federal Institute for Plant
sciences have created genetically engineered rice that contains
unusually high content of Beta
-
carotene (vitamin a).


Genetically modified rice in Asia is extremely essential as it is part of
their traditional diet.





Advantages

Nutrition


However, anti GMF protests in Europe could mean that this nutritionally
enhanced rice may not even enter the market at all.


Preservatives become unnecessary as the “shelf life” of these foods can be
engineered to last longer before rotting therefore, nutrition is not deterred by
preservatives


This also aids with importing and exporting food because expiry dates are
less of a concern


Many individuals believe that genetically modified foods taste better hence,
increase in nutrition appears not to detriment but enhance taste



Medicines and vaccines are expensive to produce and sometimes
require special storage conditions which are not readily available
in third world countries.


Researchers are working on to engineer tomatoes and potatoes so
that these crops can contain edible vaccines. These would not need
special storage, and will be much easier to ship, don’t need
injecting.


The DNA system of some foods are modified in order to prevent
the consumer from experiencing an allergic reaction therefore,
permitting people to eat foods that they would otherwise be
unable to consume. Ultimately, this contributes to the variety of
food available to individuals of society.





Advantages

Medicine


Soil and groundwater pollution is a huge issue in all parts of the
world.








So plants such as poplar trees have been genetically engineered to
clean up heavy metal pollution from contaminated soil.





Advantages

Detoxification


Time can be saved as some foods can be genetically engineered to
increase the speed of food production (in comparison to
traditional methods).


Rapid growth can aid poorer nations with greater populations as
more supply becomes available to the overwhelming demand.


Increased productivity helps the economy.


Food production increased and developed countries by 70%,
because of genetically modifying technology.





Advantages

Economy


Just like how some species of mosquitoes evolved to develop
resistance to now
-
banned pesticide DDT, many people think that
insects will become resistant to B.T. or other crops that have been
engineered to produce their own pesticides.


The claim of ending world hunger with GM food is a false claim.
World hunger is not caused by shortage of food production, but by
sheer mismanagement, and lack of access to food brought about by
various social, financial and political causes.





Disadvantages
-

Environmental

Ultimate Effectiveness


Another question raised is that what if crop plats that engineered
for herbicide tolerance cross breed with weeds, resulting in
transfer of herbicide resistant genes from the crops into weeds.


This would make ‘
super weeds’

that are tolerant to herbicides as
well which may ultimately, cause crop failure.





Disadvantages
-

Environmental

Unintentional Gene Transfer


Other genes may cross over into non
-
engineered crops plant next to GM crops.


An ‘escape’ of genetic material into the environment can be extremely
detrimental.


Some of the genetically modified foods contain vaccines, antibiotics,
contraceptives etc. Therefore, ultimate result could be extremely hazardous to
animal health and the environment.


This possibility is shown by defence of farmers that against the lawsuit filed by
Monsanto. Monsanto has filed patent infringement lawsuits against farmers who
may have harvested GM crops. Monsanto claims that farmers obtained Monsanto
-
licensed GM seeds and did not pay royalties to Monsanto.


But farmers claim that their unmodified crop were cross
-
pollinated from someone
else’s GM crops from a couple of fields away. Although, more investigation is
needed to solve this issue this is a good indication that more debates like this can
take place in the future.




Genes exchange between plants through pollen. 2 ways to make
sure that untargeted crops will not receive the genes from GM
plants are to engineer GM plants that are male sterile (can’t
produce pollen) or to further modify the same GM crop to GM
plants so that the pollen doesn’t contain the introduced gene.


Another solution is to create buffer zones around a field of GM
crops.


Ex: Non
-
GM corn would be planted to surround a field of B.T. (GM)
corn, and the non
-
gm corn would not be harvested. So pests would
refuge in non
-
GM corn and could be allowed to destroy it so they will
not develop resistance to B.T. pesticides.





Disadvantages
-

Environmental

Solutions

This whole concept of genetically modifying or enhancing fruits
and vegetables is an example of invasive species, as it is only
through genetic alterations that these foods are produced. This
means that, similarly to the new introduction or foreign or
invasive species, GMF`s also may have the negative affect that are
brought to the environment through invasion species. These
negative effects can be devastating to various communities around
globe. Some of these affects include:





Disadvantages
-

Environmental

Invasive Species Comparison


Alteration of the food chain in an environment


Endangerment of many plants, foods, and even animals



Species would become endangered as a result of their food becoming endangered
or extinct

a)
some reasons for endangerment is that the GMF`s may begin to
compete for living necessities with other species, and in the end
out
-
competing them, resulting in the food chain to be altered, as
stated previously.

b)
) This is an example of predation, where the GMF’s, acting as the
predator, are benefitting



Predation
-
predation is when one organism benefits off of another organism but
the organism that is not benefiting is being harmed.


When predation occurs not only will one species be affected but the balance of
certain species population will begin to alter. This is because when one species
begins to decline in population numbers other species, which are consuming these
species, will have to compete more as a supplement. As the population of the food
sources declines, the competition between the predators, higher up on the food
chain, begins to intensify in an attempt to continue to survive.




This is one of the most crucial cons: predation, when the food chain is
affected, everything species in that food chain is affected. This would have
negative effects on:


Economy:

food production decreases, and a lower population animals would
result in things such as fewer quantities of meat and fur. Also if production of
these things decreases, there would a decrease in the amount of exports occurring,
having drastic effects on major companies and businesses.



Social:

If foods are beings effected by GMF’s through predation, they start to face
endangerment, meaning that the food stocks go down. People will have to either
give up tradition foods as food prices will inflate, in order to keep constant the
demand versus quantity of the product ratio.



Ethical:

Even in our modern day and age, people still follow their ancestral
customs of living. They still rely on certain foods and animals to continue their
lives, an example being farmers. If there is not enough production occurring then
cannot make a living, let alone the fact that food production would go down.



Many people have developed life threatening allergies to peanuts
and other foods; a possibility that introducing a new gene in a
plant may create a new allergen or causing an allergic reaction in
susceptible individuals.






A proposal to introduce a gene from Brazil nuts into soybeans was
rejected due to fear of causing unexpected allergic reactions.


Extensive testing of new GMFs may be required to avoid possible
harm which makes GMFs expensive to put into market.





Disadvantages


Human Health

Allergenicity



Because this branch of science is relatively new, the long
-
term
effects of genetically modified food on animals including humans
remains undetermined


Individuals fear that chemical additives utilized in the process of
producing genetically modified foods will be detrimental to the health
of the consumer.


Some individuals believe that consuming GM foods contribute to
diseases that are immune to antibiotics


Experts have gathered evidence which suggests that consuming
these foods promotes the development of cancer cells.





Disadvantages


Human Health

Unknown Ultimate Effects


Consumer is unaware of how their food is genetically modified unless they
research


Ex: Modified Milk Ingredients


What about it is modified?


In some countries, some countries neglect to mention on food labels that
they use genetically modified foods as ingredients.


Scientists can choose which genes to manipulate, but they don't yet know where
in the DNA to precisely insert these genes and they have no way of controlling gene
expression. Genes don't work in isolation, changing a few could change the whole
picture, with unpredictable and different effects under different circumstances.



Which One’s the Modified Milk?


Determining whether a product is safe is extremely subjective as
an individual is hindered by their emotion and perspective so
although some scientists claim for GM products to be safe, the
degree of safety remains debatable.


Science in unable to prove a negative such as “GM products will
not cause harm”


too many factors need to be considered and
inductive reasoning (which is f lawed) from tests must be
employed.





Disadvantages


Interesting Views

Philosophical Perspective


Religious and cultural communities fear the consequences of
interfering with nature.


Mixing plant genes and animal genes together is not a comfortable
idea for some individuals


Crosspollination between animals and plants can have potential
detrimental effects on other organisms existing within an
environment


Ex: Flora and fauna diversity will decrease





Disadvantages


Interesting Views

Religious Perspective