Effects of Genetic Engineering - adaptingtotheenviroment


12 déc. 2012 (il y a 9 années et 2 mois)

743 vue(s)

Effects of Genetic Engineering

By Mary Lynn Bushong


It seems like something out of a science fiction novel:
scientists using gene splicing to improve food production plants
so more could be grown with less. It sounds wonderful on the
surface, but can it stand up to serious testing?


What is involved in making plants more efficient? There are
two ways of doing this. The first is through traditional plant
breeding practices of selecting and crossing plants of the same
kind for
certain traits. If you were growing corn and wanted to
grow shorter corn, you would select plants that were shorter and
cross those until you came up with a plant that was the height you wanted.


Gene splicing, on the other hand, is completely diffe
rent, although some people
think it is the same. It involves the splicing or cutting in of genes from a
completely different plant or chemical chain and adding it to another one. It is not
something that could naturally occur in a plant otherwise.


Scientists use a virus to carry the new genetic material to the DNA chain of the
plant they are changing. Normally, there are controls built into the DNA strands so
it knows to do certain things at certain times. This new part of the DNA acts
differently f
rom the rest of the strand. It has no controls. Instead of turning on and
off when necessary, it works all the time. The result is that it can produce new
compounds and chemicals never seen before in that or any plant. What the plant
produces depends on wh
ere the new DNA was put into the existing strand. Many
people worry that the new substances that are produced can be harmful to people
and animals.


This gene splicing technology can affect us in different ways. The first way is
through foods we reg
ularly eat. After little testing and relying mostly on the word
of the manufacturers that the food products were safe, the first genetically
engineered foods were allowed on the market. To avoid scaring people from using
these "Frankenfoods," as they have
been labeled by some, the government said
they did not have to be labeled.


The problem comes if parts of plants like peanuts are added to something like
corn. If you have a bad allergy for peanuts, you know to avoid those and to read
labels to see
if it is in an ingredient list. What would happen if a scientist added a
part of peanut DNA to that of corn? Let's say that the experiment was a success,
and the corn was really improved. What would happen if that corn was widely
grown for a specific purpo
se, and some of that corn was sold for something else,
and it made its way into our food chain? Since that corn would be unlabeled, how
might that affect those who have serious problems with any kind of peanut
product? This is just one of many concerns voi
ced by scientists.


Monsanto now sells genetically engineered soybean seeds that are "Round

ready." This means that some of the weed killer Round Up

is part of the
DNA of the plant. That means a farmer can spray his field of soybeans with Rou

to kill the weeds and not harm the plants. Since consuming even a small part
of this weed killer can make you sick or kill you, what affect does this have on the
people who eat soy products from these plants? No one knows for sure because

testing is incomplete. Japanese scientists do report that 3 harmful
substances were much higher in the engineered beans than non
engineered beans
after being heated. Soy is one of the most widely used plant products in the world.


On a wide scale,
genetic engineering can have another effect. Two companies
have come out with what is called terminator wheat. A farmer can plant this type
of wheat, and it grows well and produces a good harvest. All the seeds that are
produced, however, will not grow. Fo
r farmers who are rotating their crops, this is
helpful because it means they won't have bits of wheat coming up in that field the
next year.


There are problems with that, though. A farmer cannot keep back some of the
seed to grow the next year. He

always has to go back and buy more. This could be
very hard on farmers in third world countries as well. They would no longer be
able to save seed, but would have to pay more to buy it. It would eliminate their
sufficiency. Then there is the problem
with cross pollination. Perhaps you are
growing a different kind of wheat, and it crosses with the terminator wheat. It
could affect that other variety and make it useless for seed.


As genetically engineered crops become more common, it is more li
kely they
will cross with traditionally
bred fruits and vegetables. It may make it more
difficult to obtain traditional varieties and so deplete the plant gene pool.


Some people worry that this plant engineering will lead us to problems with

weeds. These are weeds that cannot be controlled with conventional weed
killers. It is also possible that improperly used genetically engineered plants can
affect their wild cousins. Those genes are spliced using plant viruses which can
mutate later on an
d destroy other plant species with no controls.


There is much that still needs to be studied in genetically engineered plants. It
is possible that some of them might hold the key to feeding a hungry world as the
population grows larger. If that is the case, however, governments need to test for
term safety before these engineered plants are allowed out of the laboratory. It
can sometimes take years of exposure for problems to turn up. These studies
should test long
term effects before the engineering genie is all the way out of the


The biotech companies could be at the dawning of a brave new world or be on
the cusp of an environmental disaster. Time will tell which one it is to be.

Name _____________________________

Date ___________________

Effects of Genetic


What is one way of making plants
more efficient?


Scientists use a plant ______ to carry
genetic to the new DNA strand.






Why would using a plant virus to
carry a spliced gene

possibly cause
problems later? Answer: Possible
mutation to affect other kinds of


How does plant breeding differ from
genetic engineering?


What effect does the spliced DNA
have the rest of the strand?

It makes

the strand produce
better substances.

It makes the strand produce
different substances.

It makes the rest of the strand
work better.



What is one of the dangers of having
unlabeled genetically engineered


What is
terminator wheat?


How would a super weed affect the

Effects of Genetic Engineering

When you think of genetic engineering, what do you think of?