POGIL Activity: Genetically Modified Foods - Manage OSLN STEM

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11 Δεκ 2012 (πριν από 4 χρόνια και 4 μήνες)

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POGIL Activity: Genetically Modified Foods


Name ____________________________ Date ________________ Period _____


Genetically modified foods have had foreign genes (genes from other plants, animals or
bacteria) inserted into their genetic codes th
rough a process known as genetic
engineering.
Combining genes from different organisms is known as
recombinant DNA

technology
, and the resulting organism is said to be
genetically modified

(GMO)
,
genetically engineered
, or
transgenic
. GM products include
medicines and vaccines,
foods and food ingredients,
animal feed
, and fibers.


Objectives:

1.

The learner will be able to inv
estigate and analyze the
genetic engineering
technology used
to create
genetically
modified foods
.

2.

The learner will be able to
compare

and contrast the benefits and potential risks
of genetically modified organisms.


Model 1






1.
Using
the information provided in
model 1,
w
hat types of plants can be genetical
ly
modified using gene splicing?



2. What is gene splicing?





10

minutes


3
.
Name and briefly describe the


source organism”
that is providing

the gene

for t
his
genetic engineering example.



4
.
What is the name of the desired
bacterial gene, and what property of this gene is
of
interest to agricultural scientists?



5
. Why do you think genetic engineers would w
ant to create Bt transgenic corn and
cotton?







Model 2






10

minutes

1.

Examine the graph

shown in Model 2. What genetically engineered crop is most
widely grown in the U.S.?


2. According to the graph, when were genetically modified food crops adopted by the
U.S.?


3. In the year 2007, what percentage of U.S. land acres wer
e used to grow Bt cotton?



4
. Make a prediction: If the graph were to show data from 2007


2011, would you
expect GMO
’s

in the form of food crops to increase or decrease? Support your answer
with a brief explanation.






5
. GM foods are genetically en
gineered for a specific purpose or attribute (desired
characteristic). Use Table 1 to list four reasons why crops are genetically modified.











Model 3



Study the
diagram showing a piece of bacterial

DNA that is resistant to cold
temperatures being spliced into a strawberry plant’s

DNA. Arrange the diagrams in
order by writing the letters
A
(first) through
D
(last) in the spaces provided.





5.
What would be an ad
vantage of splicing a naturally
-
occurring cold
-
resistant bacterial
gene into a strawberry plant?



5 minutes

Model 4



Genetically Modified Food: The Benefits and the Risks


Genetically modified foods or GM foods for short, also go under many different

names,
including transgenic food, genetically
engineered

food or biotech food.


So what are GM foods? Although different people and groups have different definitions,
GM foods can broadly define as foods that "are produced from crops whose genetic
makeup
has been altered through a process called recombinant DNA, or gene splicing,
to give the plant a desirable trait." The modification is usually done in the lab using
molecular techniques or genetic
engineering

although there are others who would argue
that
crops produced through conventional breeding can also be considered as GM food.


The first GM food crop, a tomato developed by Montsanto was submitted for approval to
the US FDA in August 1994 and came into market in the same year. As of September 9,
2008,

a total of 111 bioengineered
food products

have completed the US FDA
"consultation procedures" on bioengineered foods. In addition to the tomato, the range
of products includes soybean, corn, cotton, potato, flax, canola, squash, papaya,
radicchio, sugar
beet, rice, cantaloupe, and wheat. According to estimates by the
Grocery Manufacturers of America, "between 70 percent and 75 percent of all
processed foods available in U.S. grocery stores may contain ingredients from
genetically engineered plants. Breads
, cereal, frozen pizzas, hot dogs and soda are just
a few of them."


The benefits of GM foods:

Support for GM foods come from different sectors:
scientists, economists, and understandably from the agricultural and food industries.


1.

GM foods can fight world

hunger. The world population has reached an all
-
time
high of over 6 and a half billion. Over 20% of these are suffering from poverty
and hunger. That GM foods can stop hunger is one of the noblest motivations
behind the development of GM foods. GM foods s
upposedly are easier to grow
and bring higher yields.

2.

GM crops are better. GM crops are designed to be sturdier and more robust than

their non
-
modified cousins. They are meant to be resistant to drought, diseases,
and pests.

3.

GM foods can fight
malnutrit
ion
. In a world suffering from malnutrition, GM foods
can answer the need for more nutritious food. To cite an example, Swiss
research strove to create rice strains that contain large amounts of beta
-
carotene
and iron to counteract vitamin A and
iron defic
iency
. Malnutrition can refer to both
under
-
nutrition and wrong nutrition.

4.

GM foods are good for the environment. GM foods translate into less use of
pesticides, herbicides and fertilizers, and therefore less pollution.

5.

GM foods are safe. The FDA ensures

that foods made from these plants are
safe for humans and animals to eat, the USDA makes sure the plants are safe to
grow, and the EPA ensures that pesticides introduced into the plants are safe for
human and animal consumption and for the environment.


T
he issues against GM foods
:


1.

GM foods are for
profit
. According to its opponents, GM foods were created for
profit and nothing else.

20 minutes

2.

GM foods are unregulated. The use of GM foods in the world is almost an
unregulated free
-
for
-
all activity. Going through th
e US FDA consultation
procedures is mainly voluntary.

3.

There are also
reports

of GM plants escaping field trials and finding their way to
the natural environment, thousands of miles away. In 2006, rice which contained
genes from the bacteria
Bacillus thurin
giensis

(the notorious Bt) found its way to
European supermarkets, causing a big outcry. The bacterial gene rendered the
rice resistant to insects and the transgenic rice was a test plant that has not yet
been approved for human consumption.

4.

GM foods can h
arm the environment. GM foods are affecting their environment
and some of these effects might actually be harmful. The effects are especially
evident in other living organisms within the vicinity. There are concerns, for
examples, how cross
-
pollination wi
th pollens from GM plants can affect non
-
GM
plants.

5.

GM foods can be detrimental to human health. The main concerns about adverse
effects of GM foods on health are the transfer of antibiotic resistance, toxicity and
allergenicity. With genetic modifications

come new compounds in the crops
which we virtually know nothing about.


Your Opinion
: Are you for or a
gainst genetically modified food
? Discuss at least
3
facts from the article that support your opinion.