BIOTECHNOLOGY
Student Learning Objectives. Instruction in this lesson should result in
students achieving the following objectives:
1 Describe biotechnology and genetic engineering.
2 Explain the differences between genetic engineering and traditional plant
breeding.
3 Explain the steps in engineering a plant.
4 Explain how desirable genes are located.
5 Explain how selected genes are introduced into a target organism.
6 Explain how genetically engineered crops are tested.
7 Discuss the benefits and risks of biotechnology.
Anticipated Problem: What are biotechnology and genetic engineering?
I. Biotechnology and genetic engineering are often confused. Biotechnology includes
genetic engineering but it also involves much more.
A. Biotechnology is simply the use of living organisms to create or improve something.
Today biotechnology is centered on the modification of living organisms as a result of
our new understanding of genes and DNA. It includes techniques such as:
1. Genetic engineering
2. DNA analysis
3. Genetic mapping
4. Gene transfer
5. Plant tissue culture
6. Biofermentation
B. Biotechnology is being used with microbes, plants, and animals to produce beneficial
products and improve species. It is being applied to many agricultural processes
including:
1. Bread making
2. Beer brewing
3. Wine, cheese, and yogurt fermentation
4. Silage fermentation
5. Classical plant breeding
C. Genetic engineering is the manipulation of genes. It is also referred to as recombinant
DNA technology. This involves moving genetic information from one organism into a
different organism or replacing it in the original organism in a new combination. These
changed organisms are called transgenic. A transgenic organism is one that has either
new genetic information incorporated into itself or a unique recombination of its original
DNA.
Anticipated Problem: How is genetic engineering different from traditional plant
breeding?
II. Genetic engineering (GE) is different from traditional plant breeding (TPB) in many
ways:
A. With TPB, crosses can be made only within the same species or closely related
species. This limits the genetic material breeders can work with. With GE, there are
fewer limits to the genetic material a breeder can work with. Genes can be taken from
any living organism including bacteria or animals and inserted into a plant.
B. When plants are crossed using TPB, nearly 100,000 genes are combined from each
plant. This requires breeders to employ the technique of backcrossing, rebreeding back
to one of the original parents, many times to get rid of unwanted genes and restore
desired traits. With GE, a single desired gene can be inserted into a plant.
C. When a cross is made using TPB, the seeds are collected and the new generation of
plants must be germinated and grown before the results of the cross can be verified.
Using GE, modified plants are grown in tissue culture and the change is verified.
D. TPB requires up to 14 generations to produce a new plant. GE will create a new plant
in as few as five generations.
Anticipated Problem: What steps are involved in engineering a plant?
III. The creation of a transgenic organism begins with a selected gene from a donor
organism and the insertion of that gene into a host organism. Eight major steps are
required to complete this process.
A. A donor which contains the gene that codes for the desired trait is identified.
B. DNA is removed from this organism’s cells and cut into fragments.
C. Fragments of DNA are sorted by size using gel electrophoresis and grouped. The
fragment containing the desired gene is then isolated.
D. The targeted fragment is joined with new DNA, making it possible to move the
desired gene into the host organism.
E. The altered DNA is moved into the host cells.
F. These transformed cells are grown into a complete transgenic organism.
G. This transgenic organism is grown and tested.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 5
H. The transgenic organism is reproduced to assure that the new gene is transferred to the
progeny.
Anticipated Problem: What methods are used to find a specific gene within an
organism?
IV. Creating a transgenic organism begins with locating the specific gene that codes for
the desired trait. Genes are specific sequences of DNA contained among all of the DNA
inside an organism’s nucleus. In most plants and animals, less than ten percent of the
DNA code for genes. A scientist will use a variety of mapping techniques to find a
specific gene. There are three kinds of gene maps: genetic linkage maps, physical marker
maps, and DNA sequence maps.
A. Genetic linkage maps show where on the chromosome a target gene may be. It will
provide the general proximity. These linkages are determined by examining the
frequency that different traits are inherited together.
B. Physical marker maps identify the distance between a marker and the desired gene
along the strand of DNA. Markers are specific molecular characteristics of the DNA
molecule which can be observed.
C. DNA sequence maps describe the order of the bases (ATGC) around and including the
target gene on the DNA strand within the chromosome.
Anticipated Problem: How are selected genes introduced into a target organism?
V. Introducing a new gene into a target organism is a complex process in which many
obstacles must be overcome.
A. The desired gene must be cut out of the donor organism and combined with other
DNA before it can be inserted into the target organism. This combination is necessary
for the gene to function, replicate, and be inheritable. This recombined DNA is usually
a plasmid, a self-replicating closed loop that comes from a bacterium. Once inside the
host cell, the plasmid can replicate and be passed on to the next generation.
B. The target cell must remain intact after the transfer or it will not function. These cells
must not be ruptured or they will die. The tough cellulose cell wall must be penetrated
and the new DNA gently moved through the cell membrane.
1. Enzymes can be used to digest the cell wall, creating an exposed membrane.
Temporary holes are opened in this membrane to allow gene transfer. Plant cells with no
cell wall are called protoplasts and are very susceptible to gene transfer.
2. A microorganism that naturally penetrates plant cells can be used to transfer DNA
into the target cell. This technique leaves the cell wall intact.
C. There are four methods commonly used to transfer genes and create genetically
modified organisms: microinjection, electroporation, biolistics, and vectors. A technique
called viral encoding does not create a genetically transformed organism but does result
in an organism that produces a foreign protein.
1. Microinjection: DNA is physically injected into a cell. A small glass needle is moved
through the cell membrane. After the needle has penetrated the membrane, the new
DNAis simply injected into the cytoplasm. Transformed cells are grown into whole
plants that exhibit the desired trait, reproduced so the offspring contains the new
gene.
2. Electroporation: Placing a protoplast into an electrically charged environment can
cause the cell membrane to become permeable to DNA. The technique of
electroporation uses an electric charge to open holes in the cell membrane, allowing
foreign DNA to enter the cell. The transformed cells are grown and propagated,
with the subsequent generations exhibiting the new trait.
3. Biolistics: In this process, DNA is shot into a cell attached to microscopic metal
particles. These particles are fired from a specially modified .22 caliber gun. The particles
move so fast that they can penetrate the cell membrane without doing permanent
damage to it. Cells that survive this process are transformed and can be grown
and propagated.
4. Vectors: A living organism, such as a virus or bacterium, or a plasmid which carries
new genetic information into a target cell is a vector. The desirable gene is spliced
into the DNA of the vector. The vector than penetrates the target cell as part of its
natural life cycle and transforms the target cell through this infection.
5. Viral encoding: In this process, a virus is used to carry a new gene into a cell. This
gene does not become part of the cell’s genetic make up and so is not transferred to
future generations. While the cell is alive and infected with this virus, it will produce
the protein the new gene codes for. This technique is useful in culturing single cell
organisms to produce things such as insulin, antibiotics, and many vaccines.
D. Many techniques have been developed to identify genetically transformed plants.
These include the use of reporter genes or marker genes, DNA probes, and
immunoassays. These methods can be used to identify a genetically modified plant at any
stage of development, from seed to mature plant.
1. Reporter genes: These genes are also referred to as markers or marker genes.
Reporter genes code for an observable trait and are attached to the desired gene
before transfer into the target organism. If the reporter gene is functioning, then the
desired gene will also function. These markers are selected for traits that can be verified
early in the plant’s development.
2. DNA probes: This is a short piece of single-stranded DNA with the complimentary
code for the desired gene. It is labeled with radioactivity. If the gene is present, the
probe will stick and the radioactivity will be detected in the transformed cell. If the
gene is not present, the probe will not stick so there will be no radioactivity detected.
3. Immunoassays: These are capable of detecting the presence of the actual desired
gene without the use of markers or radioactivity. They accomplish this by identifying
the gene product, or protein, that the desired gene produces. Immunoassays utilize
techniques working with animal immune systems involving antigens and antibodies.
An animal is injected with the target protein. This is registered as an antigen
by the animal’s immune system. The animal produces an antibody in response to
that specific antigen. These antibodies are used to detect the presence of the desired
gene. These antibodies can be linked to chemicals that change color, so a simple
color change can proclaim the presence of the desired gene product.
Anticipated Problem: Where are transgenic plants tested?
VI. Genetically modified plants must be tested in a variety of ways before they can be
marketed.
A. Transgenic plants are tested in growth chambers and field trials.
1. The growth chamber is a closed environment designed to control and optimize factors
that affect plant growth. This controlled environment allows researchers to test
the new plants for traits that may harm the environment, speed the growth rate of
the plants, and evaluate the expression of desired traits.
2. Field trials are conducted outside in a controlled, natural environment using normal
production techniques. Evaluation of these trials involves much data because of the
natural variability of a field. Analysis of collected data must account for the effects of
weather, soil, pests, and any other naturally occurring variable.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 8
B. Transgenic plants are evaluated in early stage testing to determine the answers to a
variety of important questions, including:
1. What traits do they express?
2. Can they pollinate other plants, producing fertile offspring which might spread the
new trait into wild populations?
3. Can the transgenic plants escape to become weeds?
4. Are they effective for their intended use?
5. Will they produce unintended consequences to the environment?
C. Field trials are used to test varietal differences, farming practices, and the safety of
transgenic crops.
1. Varietal trials compare transformed varieties to their normal counterpart to determine
the characteristics of the new varieties. These characteristics may include
yield, pesticide tolerance, and pest resistence.
2. Agronomic trials identify the farming practices that will give the new varieties their
best growing conditions. These can include population, row spacing, tillage practices,
or fertility programs.
3. Safety trials are used to assess any possible risk the transgenic plant may pose. These
are the same risks assessed in growth chamber trials (pollinating wild relatives,
becoming a weed). But safety trials also include looking at the potential health
effects on animals, including humans, that will consume these crops, and the potential
for the development of pest resistance in the case of insecticidal transgenic
plants.
Anticipated Problem: What are the theoretical benefits and risks of biotechnology?
VII. Biotechnology offers potential benefits and risks to the environment, global
economy, and food.
A. Environmental benefits include:
1. The reduction of pesticide use
2. Greater survival of beneficial insects
3. Reduced exposure of farm workers to pesticides
4. Increased use of environmentally friendly herbicides such as glyphosate
5. Reduction of soil erosion
6. Reduced use of nitrogen fertilizer and the subsequent pollution from nitrates
7. Early detection of disease
B. Global economic benefits include:
1. More predictable yields
2. Greater yields
3. Reduced cost of production due to the use of fewer inputs
4. New markets for crops with unique traits such as pharmaceutical properties
5. Improvements to the world food supply (increased protein content, new tolerance
to environmental extremes, improved nitrogen fixation)
6. Increased efficiency in plant breeding
C. Genetically modified foods may offer the benefits of:
1. Improved protein content
2. Improved flavor
3. Improved shelf life
4. More vitamins
5. Reduction of allergens or natural toxins
6. Improved fat levels
7. Reduced pesticide residue
D. Genetically altered crops raise a number of environmental concerns including:
1. The development of insect populations resistant to this control method
2. Reduced interest in sustainable agricultural practices because of the existence of
more resistant crops
3. Difficulties in controlling weeds due to transgenic herbicide resistant crops
4. The creation of new cultivars with unknown consequences as a result of modified
crops breeding with wild plants
5. Increased use of certain herbicides with associated environmental risks inherent to
pesticide use
6. The development of disease-resistant plants resulting in more virulent strains of the
targeted pathogen
7. Poisoned wildlife
8. Reduced genetic diversity as producers become more dependant on a select group of
varieties
9. Inaccurate predictions of environmental safety from field trials
E. Economic/global concerns of biotechnology include:
1. Increased shift to more capital-intensive farming and large farms
2. Increased seed costs
3. Corporate mergers resulting in less competition among agricultural suppliers
4. Loss of ability among producers to save seed for subsequent crops
F. The concerns about biotech foods and human health include:
1. Antibiotic resistance from marker genes
2. Hidden allergens from marker genes
3. Production of new or increased levels of toxins in food crops
4. Unknown substances occurring in foods
BIOTECHNOLOGY
Part One: Matching
Instructions: For the following statements, place the letters GE in the space provided if the
statement describes a characteristic of genetic engineering. Place the letter T in the space
if it describes traditional plant breeding.
_______1. Requires up to 14 generations to produce a new plant
_______2. Crosses are made within the same species
_______3. A single desired gene can be inserted into a plant
_______4. Requires using the technique of backcrossing
_______5. Will produce a plant in as few as five generations
_______6. Plants are grown using tissue culture
_______7. Fewer limits to the genetic material a breeder can work with
_______8. Seeds are collected and grown to verify the results of the cross
_______9. Nearly 100,000 genes are combined
______10. Genes can be taken from any living organism
Part Two: Fill in the Blank
Instructions: Complete the following statements.
1. This recombined DNA is usually a _______________, a self-replicating closed loop that comes
from a bacterium.
2. _______________ _____________ maps identify the distance between a marker and the
desired gene along the strand of DNA.
3. Plant cells with no cell wall are called _______________ and are very susceptible to gene
transfer.
4. The technique of ____________________ uses an electrical charge to open holes in the cell
membrane.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 14
5. The risks of biotechnology include _______________, _______________, and
_______________ concerns.
6. Many techniques have been developed to identify genetically transformed plants. These
include the use of ______________ ____________, _______________ ____________, and
_______________.
Part Three: Multiple Choice
Instructions: Circle the letter of the correct answer.
_______1. The use of living organisms to create or improve something
a. Genetic engineering
b. Biolinkology
c. Plasmology
d. Biotechnology
_______2. Which of the following is not a type of field trial?
a. Variety
b. Agronomic
c. Safety
d. Survival
_______3. A technique that is useful in culturing single-cell organisms to produce things such as
insulin, antibiotics, and many vaccines
a. Immunoassays
b. Viral encoding
c. Biolistics
d. Electroporation
_______4. Involves moving genetic information from one organism into a different organism or
replacing it into the original organism in a new combination
a. Genetic engineering
b. Biolinkology
c. Plasmology
d. Biotechnology
_______5. Trials that compare transformed varieties to their normal counterpart to determine the
characteristics of the new varieties
a. Variety
b. Agronomic
c. Safety
d. Survival
_______6. Has either new genetic information incorporated into itself or a unique recombination
of its original DNA
a. Vector
b. Protoplast
c. Transgenic organism
d. DNA probe
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 15
_______7. Maps that describe the order of the bases (ATGC) around and including the target
gene on the DNA strand within the chromosome.
a. Reporter DNA
b. DNA sequence
c. Genetic linkage
d. Physical marker
_______8. The technique in which DNA is physically injected into a cell using a small glass
needle
a. Biolistics
b. Microinjection
c. Electroporation
d. Vector
_______9. A living organism, such as a virus or bacterium, or a plasmid that carries new genetic
information into a target cell
a. Biolistics
b. Microinjection
c. Electroporation
d. Vector
______10. A short piece of single-stranded DNA with the complimentary code for the desired
gene that is labeled with radioactivity
a. Plasmid
b. Vector
c. Encoded virus
d. Protoplast
Part Four: Short Answer
Instructions: Answer the following questions.
1. List five risks and five benefits of biotechnology.
2. What are the eight major steps in creating a transgenic organism?
3. Transgenic plants are evaluated in early stage testing to determine the answers to a variety of
important questions. Identify two of those questions.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 16
Assessment
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 49
TS–A
Technical Supplement
BIOTECHNOLOGY AND
GENETIC ENGINEERING
Biotechnology is simply the use of living organisms to create or improve something.
Currently, biotechnology is centered on the modification of living organisms as a
result of our new understanding of genes and DNA. It includes techniques such as
genetic engineering or recombinant DNA technology, DNA analysis, genetic mapping,
gene transfer, plant tissue culture, and biofermentation. These techniques allow scientists
to locate and isolate specific genes that carry desirable traits. These genes can be moved
from one organism to another without sexual reproduction. Plant tissue culture allows us
to grow a whole plant from just a few cells. Biofermentation is a technique that allows
the mass reproduction of modified cells. Biotechnology is being applied to microbes,
plants, and animals to produce beneficial products and to improve species. It is being
applied to many agricultural processes including bread making; beer brewing; wine,
cheese, and yogurt fermentation; silage fermentation; and classical plant breeding. Today,
much of the discussion of biotechnology centers on the area of genetic engineering.
Genetic engineering is the manipulation of genes. It also is referred to as recombinant
DNA technology. This involves moving genetic information from one organism into a
different organism or replacing it into the original organism in a new combination. These
changed organisms are called transgenic. A transgenic organism is one that has either
new genetic information incorporated into itself or a unique recombination of its original
DNA. This process allows scientists to incorporate desirable genes from any living
organism into the desired plant. It also allows genetic recombination without the normal
challenges of traditional plant breeding.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 50
Genetic engineering is different from traditional plant breeding in many ways. With
traditional plant breeding, crosses can be made only within the same species or
closely related species. This limits the genetic material breeders can work with.
Genetic engineering holds fewer limits to the genetic material a breeder can work
with. Genes can be taken from any living organism, including bacteria or animals,
and inserted into a plant. This opens the door to a much greater list of possible
characteristics which could be incorporated into a plant. When plants are crossed using
traditional plant breeding, nearly 100,000 genes are combined from each plant. This
requires breeders to employ the technique of backcrossing, rebreeding back to one
of the original parents, often to get rid of unwanted genes and restore desired traits.
With genetic engineering, a single targeted gene can be inserted into or removed
from a plant. This makes species improvement much more precise. When a cross is
made using traditional plant breeding, the seeds are collected and the new generation
of plants must be germinated and grown before the results of the cross can be
verified. Using genetic engineering, modified plants are grown in tissue culture and
the change is verified early in the development of the plant. This greatly improves
the efficiency of the selection process. Traditional plant breeding requires up to 14
generations to produce a new plant. Genetic engineering will create a new plant in as
few as five generations. The creation of a transgenic organism begins with a selected
gene from a donor organism and the insertion of that gene into a host organism. Eight
major steps are required to complete this process. First, a donor is identified that contains
the gene that codes for the desired trait. Next, theDNAis removed from this organism’s
cells and cut into fragments.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 51
Technical Supplement
DNA FRAGMENTS
These fragments of DNA are sorted by size, using gel electrophoresis, and grouped
together. The fragment containing the desired gene is then isolated. The targeted
fragment is joined with new DNA, making it possible to move the desired gene into
the host organism. The alteredDNAis moved into the host cells using one of a variety
of techniques. This creates a cell that has been genetically transformed into a new
organism. These transformed cells are grown into a complete transgenic organism.
This transgenic organism is grown and tested extensively. The transgenic organism is
reproduced to assure that the new gene is transferred to the progeny with the desired
results. These processes are complex and have evolved after years of research. Creating a
transgenic organism begins with locating the specific gene which codes for the desired
trait. Genes are specific sequences of DNA contained among the DNA inside and
organism’s nucleus. In most plants and animals, fewer than ten percent of the DNA code
for genes. A scientist will use a variety of mapping techniques to find a specific gene.
There are three kinds of gene maps: genetic linkage maps, physical marker maps, and
DNA sequence maps. Genetic linkage maps show where on the chromosome a target
gene may be. It will provide the general proximity. These linkages are determined by
examining the frequency that different traits are inherited together. The DNA molecule is
too small to see but there are techniques that can be employed to detect its molecular
characteristics. These molecular characteristics are referred to as markers. When a
particular marker is found in plants that also exhibits the trait we are looking for, we say
that these events are linked. Genetic linkage maps are made utilizing records of this
linkage.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 52
Physical marker maps identify the distance between a marker and the desired gene
along a strand of DNA. Markers are specific molecular characteristics of the DNA
molecule which can be observed. These maps are made by cutting the DNA using
special enzymes called restriction enzymes. Each enzyme cuts the DNA at a different
spot and creates fragments of varying lengths. DNA probes are used to identify
markers on fragments. Inheritance data tells the researcher the probable location of
the gene near selected markers. Fragments are then aligned using overlapping
sequences. Using this information, a composite fragment is assembled into a map.
DNAsequence maps describe the order of the bases (ATGC) around and including
the target gene on the DNA strand within the chromosome. This can be done for a
portion of the DNA within an organism, or the whole organism can be mapped.
Projects are underway to map not only complete organisms, but complete species
genomes. Knowing the genome’s DNA sequences can be the first step in understanding
disease resistance or susceptibility, growth characteristics, and any other genetically
regulated traits. Once the desired gene has been identified, it must be cut out of the donor
organism and combined with other DNA before it can be inserted into the target
organism. This combination is necessary for the gene to function, replicate, and be
inheritable. This recombined DNA is usually a plasmid, a self-replicating closed loop that
comes from a bacterium. Once inside the host cell, the plasmid can replicate and be
passed on to the next generation. Before this can happen the target cell must be prepared
for the transformation. The target cell must remain intact after the transfer, or it will not
function. These cells must not be ruptured or they will die. The tough cellulose cell wall
must be penetrated and the new DNA gently moved through the cell membrane. Enzymes
can be used to digest the cell wall, creating an exposed membrane. Temporary holes
are opened in this membrane to allow gene transfer.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 53
Technical Supplement
TRANSFERRING GENES
AND CREATING GENETICALLY
MODIFIED ORGANISMS
Plant cells with no cell wall are called protoplasts and are very susceptible to gene
transfer. There are four methods commonly used to transfer genes and create genetically
modified organisms: microinjection, electroporation, biolistics, and vectors. There is also
a technique referred to as viral encoding which does not create a genetically transformed
organism, but does result in an organism that produces a foreign protein. With
microinjection, DNA is physically injected into a cell. A small glass needle is moved
through the cell membrane. After the needle has penetrated the membrane, the new DNA
is simply injected into the cytoplasm. Transformed cells are grown into whole plants that
exhibit the desired trait, reproduced so the offspring contains the new gene.
Electroporation involves placing a protoplast into an electrically charged environment.
This can cause the cell membrane to become permeable to DNA. The technique of
electroporation uses an electrical charge to open holes in the cell membrane that allow
foreignDNAto enter the cell. The transformed cells are grown and propagated, with the
subsequent generations exhibiting the new trait.
Biolistics is a method of gene transfer in which DNA is shot into a cell attached to
microscopic metal particles. These particles are fired from a specially modified .22
caliber gun. The particles move so fast that they can penetrate the cell membrane
without doing permanent damage to it. Cells that survive this process are transformed
and can be grown and propagated.
Vectors are living organisms, such as a virus or bacterium, or a plasmid which carries
new genetic information into a target cell. The desirable gene is spliced into the
DNAof the vector. The vector than penetrates the target cell as part of its natural life
cycle and transforms the target cell through this infection.
Viral encoding uses a virus to carry a new gene into a cell. This gene does not
become part of the cell’s genetic make up, and so is not transferred to future generations.
While the cell is alive and infected with this virus, it will produce the protein
the new gene codes for. This technique is useful in culturing single-cell organisms
to produce things such as insulin, antibiotics, and many vaccines.
After these transformation procedures have been followed, researchers must verify
their success. Many techniques have been developed to identify genetically transformed
plants. These include the use of reporter genes or marker genes, DNA probes, and
immunoassays. These methods can be used to identify a genetically modified plant at any
stage of development, from seed to mature plant. The use of reporter genes is one such
method. These genes are also referred to as markers or marker genes. These genes code
for an observable trait and are attached to the desired gene before transfer into the target
organism. If the marker gene is functioning, then the desired gene also will function.
These markers are selected for traits which can be verified early in the plant’s
development. DNAprobes are short pieces of single-strandedDNAwith the
complimentary code for the desired gene. For example, if the gene’s DNA sequence were
ATTGCAGTT,then the probe would be TAACGTCAA. The probe is labeled with
radioactivity. If the gene is present, the probe will stick, and the radioactivity will be
detected in the transformed cell. If the gene is not present, the probe will not stick,
and there will be no radioactivity detected.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 55
Technical Supplement
IMMUNOASSAYS
Immunoassays are capable of detecting the presence of the actual desired gene without
the use of markers or radioactivity. This is accomplished by identifying the gene
product, or protein, that the desired gene produces. Immunoassays utilize techniques
working with animal immune systems involving antigens and antibodies. An
animal is injected with the target protein. This is registered as an antigen by the animal’s
immune system. The animal produces an antibody in response to that specific
antigen. These antibodies are used to detect the presence of the desired gene. These
antibodies can be linked to chemicals that change color, so a simple color change can
proclaim the presence of the desired gene product.
Once a crop is verified as having been altered genetically, it must be tested before it
can be released into the environment. Numerous tests must be conducted, and several
separate facilities are involved. Transgenic plants are tested in growth chambers
and field trials. These provide controlled environments where needed tests can be
conducted.
The growth chamber is a closed environment designed to control and optimize factors
that affect plant growth. This controlled environment allows researchers to test
the new plants for traits which may harm the environment, speed the growth rate of
the plants, and evaluate the expression of desired traits. Field trials are conducted
outside in a controlled, natural environment using normal production techniques.
Evaluation of these trials involves much data because of the natural variability of a
field. Analysis of collected data must account for the effects of weather, soil, pests,
and any other naturally occurring variable.
During this testing, many characteristics of the new plant are evaluated. Transgenic
plants are evaluated in early stage testing to determine the answers to a variety of
important questions, including: What traits do they express? Can they pollinate
other plants, producing fertile offspring which might spread the new trait into wild
populations? Can the transgenic plants escape to become weeds? Are they effective
for their intended use? Will they produce unintended consequences to the environment?
All of these questions must be answered to the satisfaction of the researchers
and various government agencies before field testing can take place. A number of
late field trials will then be conducted before the new crop is brought to market.
Field trials are used to test varietal differences, farming practices, and the safety of
transgenic crops. Varietal trials compare transformed varieties to their normal counterpart
to determine the characteristics of the new varieties. These characteristics
may include yield, pesticide tolerance, and pest resistence. Agronomic trials identify
the farming practices which will give the new varieties their best growing conditions.
These can include population, row spacing, tillage practices, or fertility programs.
Safety trials are used to assess any possible risk the transgenic plant may pose.
These are the same risks assessed in growth chamber trials (pollinating wild relatives,
becoming a weed), but also include looking at the potential health effects on
animals, including humans, that will consume these crops, and the potential for the
development of pest resistance in the case of insecticidal transgenic plants.
As research in biotechnology brings more new products to the market, society is left
to debate the risks and benefits of these innovations. Regulators ask two basic questions:
What are the theoretical benefits of biotechnology? What are the known risks
of biotechnology? In order for any new product to reach the marketplace, the benefits
must far outweigh any potential risk. This must be verified with solid scientific
investigation. Biotechnology promises a variety of benefits, but potential risks do
exist.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 57
TS–E
Technical Supplement
BENEFITS OF
BIOTECHNOLOGY
Biotechnology offers potential environmental benefits, global economic benefits,
and food benefits. The environmental benefits include: the reduction of pesticide
use by incorporating pesticides into the plant; greater survival of beneficial insects
due to the reduction of broad spraying of insecticides; reduced exposure of farm
workers to pesticides; increased use of environmentally friendly herbicides, such as
glyphosate, as tolerant plants are introduced; the reduction of soil erosion through
the use of plants more tolerant to conservation practices; reduced use of nitrogen
fertilizer and the subsequent pollution of water from nitrates; and early detection of
plant disease.
In addition to these environmental benefits, the impact on the global economy must
also be considered. Global economic benefits include: more predictable yields;
greater yields; reduced costs of production due to the use of fewer inputs; new markets
for crops with unique traits such as pharmaceutical properties; improvements
to the world food supply through increased protein content, new tolerance to
environmental extremes, and improved nitrogen fixation. There is also the increased
efficiency in plant breeding.
Plants that are grown for food also are being modified for improvement. Genetically
modified foods may offer the benefits of improved protein content, improved flavor,
improved shelf life, more vitamins, reduction of allergens or natural toxins,
improved fat levels, and reduced pesticide residue.
Just as benefits are considered, so too must the risks be evaluated. The risks of
biotechnology include environmental, economic/global, and food concerns. Genetically
altered crops raise a number of environmental concerns. The development of
insect populations resistant to biotechnology is possible just as with any other
method of control. Resistant crops may reduce the interest in sustainable agricultural
practices. Transgenic herbicide resistant crops may become difficult to control
weeds. Modified crops may breed with wild plants to create new cultivars with
unknown consequences. There may be increased use of certain herbicides with
associated environmental risks inherent to pesticide use. The development of diseaseresistant plants will result in more virulent strains of the targeted pathogen.
There is the potential of poisoning wildlife. There may be reduced genetic diversity
as producers become more dependent on a select group of varieties. This can be
disastrous when a new pest invades an area. Field trials may not be accurate predictors
of environmental safety.
There also are risks to the global economy. An increased shift to more capital-intensive
farming and large farms may occur in some places. Seed costs will increase.
More corporate mergers will occur, resulting in less competition among agricultural
suppliers. There will be a loss of ability among producers to save seed for subsequent
crops.
The concerns about biotech foods and human health must be addressed. Antibiotic
resistance from marker genes is a concern to the human and animal health community.
Hidden allergens from marker genes may result in increased demand for more
product labeling. Production of new or increased levels of toxins in food crops is
another concern. There is a fear of unknown substances that may occur in foods.
These risks have caused concerned groups throughout the world to suggest that
genetically modified crops and the food products that contain them be labeled, giving
consumers the opportunity to avoid these products.
Even with all of the advances in technology that we have at our disposal, ethical
questions will impact the use of this technology. For agriculture to have markets for
the products it produces, the general public must be educated in the science behind
biotechnology.
Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 59