Purdue University
13-Jul-00
GMO Crops? Test Yourself with This Quiz
Library: SCI
Keywords: PURDUE GMO BIOTECHNOLOGY GENES PESTICIDES HERBICIDES
Description: Nearly half of American farms grow genetically modified crops.
A plant scientist and expert in GMO crops at Purdue University has developed
10 questions to test one's knowledge of genetically modified foods and
agricultural biotechnology.
Purdue University
News Service
1132 Engineering Administration Building
West Lafayette, IN 47907-1132
765-494-2096
FAX: 765-494-0401
July 13, 2000
Understand GMO Crops? Test Yourself With This Quiz
Source: Peter Goldsbrough, (765) 494-1334; [EMAIL PROTECTED]
WEST LAFAYETTE, Ind. -- Nearly half of American farms grow genetically
modified crops such as Bt corn or glyphosate-resistant (Roundup-ready)
soybeans. Peter Goldsbrough, a plant scientist and expert in genetically
modified crops at Purdue University, has developed 10 questions to test your
knowledge of genetically modified foods and agricultural biotechnology:
1. As a result of genetically modified crops, chemical use on farms has:
a. Gone up dramatically.
b. Gone down dramatically.
c. Gone up on some but no change on others.
d. Gone down on some crops but there is little or no change on others.
e. Not changed.
2. The first plant that was modified by genetic engineering was produced in
a laboratory in:
a. 1954.
b. 1964.
c. 1974.
d. 1984.
e. 1994.
3. Will insects develop resistance to the toxins produced in Bt corn?
a. It is impossible for insects to develop resistance to Bt corn.
b. It is unlikely that insects will develop resistance to Bt corn.
c. Under certain conditions insects may develop resistance to Bt corn.
d. It is almost certain that insects will develop resistance to Bt corn.
e. Insects are already resistant to the toxins produced in Bt corn.
4. Does Bt corn or Bt cotton only kill specific pests that damage the crop?
a. The Bt toxin kills all insects.
b. The Bt toxin kills European corn borer and other flying insects.
c. The Bt toxin kills the European corn borer and its close relatives.
d. The Bt toxin only kills the insects for which it is targeted.
e. The Bt toxin repels but doesn't kill insects.
5. When did crops become resistant to herbicides?
a. Crops have always been resistant to some herbicides.
b. After the introduction of Bt corn in 1997.
c. After the introduction of Roundup-ready soybeans in 1996.
d. Crops are not resistant to herbicides.
6. Can genes escape from genetically modified crops and jump to other
plants?
a. Yes, and often do.
b. Only to some crops, but those crops aren't genetically modified.
c. Only during rare climatic conditions.
d. No, genes cannot move from species to species without human
intervention.
7. If we make plants that survive in regions where they normally wouldn't
survive, such as very cold regions, could this cause unexpected ecological
changes?
a. No, the crops are only suited for cultivated fields.
b. It is possible that a crop might invade the surrounding ecosystem.
c. It is certain that the crop would move from the fields into the
surrounding ecosystem.
8. How long does it take to develop a new genetically modified crop?
a. Twenty years.
b. Ten years.
c. Five years.
d. One year.
e. Six months.
9. Can scientists predict with certainty where an inserted gene will go on a
plant chromosome?
a. With modern genetic techniques, scientists can insert genes
precisely.
b. Genes are inserted on the proper chromosome, but there is no control
on where it goes on the chromosome.
c. Scientists have a general idea of where the gene will go and what it
will do to the plant.
d. It's just a shot in the dark.
10. Can agricultural biotechnology reduce our dependence on petroleum?
a. Most of it.
b. Some of it.
c. No effect on petroleum use.
ANSWERS
1. Answer: d. Chemical use has gone down on some crops but there is little
or no change on others. "In some cases the use of genetically modified crops
may reduce the use of pesticides, but people are still going to use
herbicides to control weeds," Goldsbrough says. "But it can reduce the use
of some pesticides that are more likely to damage the environment, and that
is progress."
2. Answer: d. 1984. "However, genetic modification and selection of plants
has been going on for about 10,000 years, since the start of agriculture,"
Goldsbrough says.
3. Answer: d. It is almost certain that insects will develop resistance to
Bt corn. Insect resistance to Bt toxin has already been demonstrated in the
laboratory and observed in the field, according to Goldsbrough. "Insects
will eventually develop resistance to the Bt toxin," he says. "Farmers are
required to plant refuges of conventional crops and take other measures to
slow down the development of resistance in insects, but it will eventually
happen. Nobody knows when that will happen -- this is a big ecological
experiment that's going on."
4. Answer: c. The Bt toxin kills the European corn borer and its close
relatives. Scientists were not surprised to learn last summer that monarch
butterflies would die if forced to eat the Bt toxin. The European corn borer
is the larva of a moth, and the Bt toxin will kill only moth or butterfly
larvae that eat it. However, monarch butterflies typically don't eat the
corn plant. "The Bt toxins produced by Bt corn aren't species specific,"
Goldsbrough says. "But they are much more specific than flying over a field
with an airplane and spraying a general insecticide. The notion that this is
a silver bullet is wrong, but so is the idea that this is killing all
insects such as the monarch butterfly. Genetically modified crops offer a
number of advantages compared to spraying insecticides."
5. Answer: a. Crops have always been resistant to some herbicides. "If they
weren't, then farmers couldn't use herbicides such as atrazine on corn or
some of the common herbicides on soybeans," Goldsbrough says. "While there
is something novel about the herbicide-resistant crops produced through
biotechnology, there is also something that is very much the same as before.
This is more of an evolution than a revolution."
6. Answer: a. Yes, and often do. If crops are able to breed with wild
relatives, the new genes will be spread to those wild plants. For example,
sorghum can breed with the common weeds johnson grass and shattercane, and
canola can breed with wild mustard plants. "So if you made Roundup-ready
sorghum you'd quickly end up with Roundup-ready shattercane," Goldsbrough
says.
Scientists safeguard against this by not releasing genetically modified
crops in areas where wild relatives are present. "There are no relatives of
maize [corn] and soybeans in the United States where the crops are planted,"
Goldsbrough explains.
Scientists did develop a technology that would prevent this crossover by
making the genetically modified crops sterile. However, the technology came
under attack from environmental groups, which labeled it the "Terminator
gene," and the technology never made it to market.
7. Answer: b. It is possible that a crop might invade the surrounding
ecosystem. "I don't think that's a likely scenario, but it could happen,"
Goldsbrough says. "For example, if you make strawberries that can resist
frosts, you may have made the plant more competitive under certain
conditions, and it is possible that it could become an exotic weed like wild
mustard. That's something that's difficult to predict."
8. Answer: b. Ten years. "At the moment it takes approximately 10 years to
develop a new genetically modified crop," Goldsbrough says. "It takes
several years to test these genes to see how they work. Then the crops are
evaluated under different environments over several years, just as other
crops are evaluated before they're released to the growers. It's a long,
careful process. That doesn't mean it's foolproof, but it's a deliberate
process." Goldsbrough says new advances in technology, such as genomics, may
speed the process of discovering desirable genes, but bringing new
genetically modified crops to market will still take several years.
9. Answer: d. It's a shot in the dark. In some cases, a literal shot. For
the most part, genes are moved into plants in one of two ways: using
bacteria as carriers, or using air guns that shoot the genetic material into
the cells. Just a few years ago scientists used .22 caliber blank cartridges
to shoot the genes into the cells, giving the technique the label "gene
gun." Once the genetic material is in the cells, the plants incorporate the
DNA into their own chromosomes. But because scientists have no control over
where the genes might go in the plant cells, they must germinate, grow and
test hundreds or thousands of plants to find the ones where the introduced
genes work properly and produce the desired traits. "The current
state-of-the-art technology is unpredictable. Where the genes end up is a
random process and can have unanticipated effects," Goldsbrough says. "But
the plants that don't have the appropriate characteristics are discarded."
10. Answer: b. Some of it. "Plants harvest the energy in sunlight, the
ultimate renewable resource, and plants are being developed that will
produce plastics, fuels and other high value products. This has the
potential to reduce our consumption of petroleum-based products.
Biotechnology may allow us to reduce our reliance on fossil-based fuels,"
Goldsbrough says.
swt/0007 AP Goldsbrough.cropquiz
Writer: Steve Tally, (765) 494-9809; [EMAIL PROTECTED]
Related Web sites:
Goldsbrough's professional web site:
http://www.hort.purdue.edu/hort/people/faculty/goldsbrough.html
Biotechnology time line: http://www.ncbiotech.org/aboutbt/timeline.cfm
International Food Information Council Foundation survey on consumer views
on biotechnology: http://ificinfo.health.org/foodbiotech/survey.htm
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