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About this Article
Written by: Ola Bant
Written on: October 13th, 2008
Tags: health & medicine, food & drink, biomedical engineering
Thumbnail by: Weller/U.S. Department of Agriculture
About the Author
Ola Bant studied at the University of Southern California in 2008.
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Volume X Issue IV > Genetically Modified Crops: Boon or Bane?
The genetic manipulation of crops such as soybeans, maize, canola, and cotton has the potential to increase crop production and sustain our the world's population. However, from the first theories of selective breeding and Gregor Mendel's hereditary factors to contemporary practices of DNA splicing, the practice of genetic modification has been fraught with controversy. Selecting the most desirable genes in a plant species can lower the time and cost of food production, increase the nutritional value, and help prevent susceptibility to disease or spoiling, thereby helping to solve some of the world's food shortage problems. However, there are setbacks to pursuing this technology. The widespread use of pesticides on genetically modified crops may bring an evolution of bacteria, weeds, and insects with greater pesticide resistance. Also, accidental transgenic splicing may result in food that are unintentionally allergenic or bring serious medical risks. For this reason, federal governments and consumers must decide to what degree and under what circumstances genetic manipulation should be performed.
Imagine a technology that could feed the 923 million people worldwide who suffer from hunger [1]. Imagine a way to prevent food from spoiling and significantly lower its production time and cost. Such technology already exists in genetic modification.
Crops are the main genetically modified (GM) product. Most harvests of the "big four" crops - soybeans, maize, canola, and cotton - in the United States are genetically modified. GM crops have numerous advantages, yet many countries strictly regulate their cultivation. The future of GM crops remains a vital debate, as its applications have several advantages and disadvantages to be considered.

Development of Genetically Modified Foods

The topic of genetic manipulation has been studied since the late 1800s, even before the discovery of the genetic material, DNA. Selective breeding was the first method of genetic manipulation. The immense technological advances of the 20th century allowed for a second method to emerge, the transgenic manipulation of a single gene. Today, both techniques are put to use to genetically modify crops.

The Concept of Heredity

Encyclopedia Britannica/http://ww​w.britannica.com/
Fig​ure 1: Mendel’s Law of Independent Assortment.
In the late 19th century, Gregor Mendel conducted the first genetic modification research and discovered the basic principles of inheritance. Known as the "father of modern genetics," Mendel cultivated different types of pea plants and studied their modes of reproduction by cross-breeding purebred specimens. He learned that each physical characteristic of the plant originates from two units of heredity, one from each parent. He named those hereditary units "factors", now known as genes.
In one of his experiments, Mendel selectively bred yellow round pea plants with green wrinkled peas (see "parental generation" in Fig. 1). The first generation (F1) offspring had a set of characteristics from only one of the parents: yellow color and a round shell. Mendel identified those traits as dominant, and the green wrinkled traits as recessive. When he self-crossed the F1 generation, a range of new characteristics emerged in the second generation (F2) offspring. In addition to the yellow-round and green-wrinkled characteristics of the parents, the second generation contained yellow-wrinkled and green-round peas (see "F2 generation" in Fig. 1).
Mendel concluded that different factors such as color and roundness are inherited independently from one another, thus obtaining progeny with various combinations of traits. This simple selective breeding process was the first form of genetic modification. Since then, the science of genetics has undergone tremendous development. Today, a single gene can be manipulated to obtain a desirable characteristic.

Techniques of Genetic Manipulation

The basic principle of the GM technique is the transfer of genes from one organism to another in order to change its characteristics. Genes of essentially different organisms such as bacteria and plants can be hybridized to form a novel transgenic entity.
Sepehr Dehpour/Illumin
Figur​e 2: Step-by-Step Schematic of the Genetic Modification Technique.
The first step of the transgenic process is the isolation of the bacteria's entire DNA. The genomic sequence is then treated with a special enzyme that identifies the desired gene and cleaves it from the original DNA molecule. Next, the targeted gene is incorporated into a plasmid, a type of circular DNA molecule found in bacteria. The plasmid replicates independently, allowing it to propagate, creating many copies of the gene. Once the recombinant plasmid had been amplified, it is added to wounded leaf fragments on a growth media. A copy of the target gene is released from the plasmid and transferred to the plant cell, where it integrates into the plant's DNA. The new plants grown from these cells contain the foreign bacterial gene (see Fig. 2 for GM technique steps). Once the cloned prototype is made, it can be commercially bred with great ease.