Genetically Engineered Foods or Organisms
Genetically Engineered Foods or Organisms
Genetically modified crops (GMCs) are plants having DNA altered through genetic engineering techniques. The goal is to introduce a new desirable trait to a plant that does ordinarily occur in the species. Desirable characteristics include resistance to environmental conditions, resistance to diseases and specific pests and production of a particular nutrient. Genetic engineering takes place in five distinct steps. First, there is DNA extraction that involves the removal of DNA from the desired organism to acquire the gene of interest. The second step is gene cloning involving separation of a single gene of interest from the rest of the extracted genes. Scientists design the gene for it to work in a different organism by separation and replacement of gene regions. Tissue culture propagates callus masses of undifferentiated plant cells, where introduction of the new transgene will take place. Methods such as gene gun, electroporation, Agrobacterium and microfibers transport the new gene to the cell of the plant cell. The transgenic plants are then grown in greenhouses until they are mature enough to produce seeds. Finally, breeders produce a high yielding transgenic line through backcross breeding using the seeds. It can take six to 15 years for completion of the process (Agbiosafety.unl.edu, 2013). Specific promoters used depend on the area where scientists want expression of the gene shown. For example, endosperm specific promoters are used if the gene expression is meant to affect the rice grains only. The artificially inserted gene should be denatured by heat administered when cooking to prevent undesired effects.
Advantages of Genetically Modified Foods
Many uses of genetic engineering benefit consumers, farmers and the agricultural industry. Genetic engineering introduces useful traits that are hardly developed using breeding. The study of horizontal gene transfer led to the discovery of genetic engineering. In 1875, a cross between wheat and rye created a genetically engineered hybrid cereal (Chen, 2010). Scientists add genes to the plant's genome to alter the genetic makeup through plant tissue culture and mutual induction. The biolistic method and medicated transformation are the most common types of genetic engineering methods. Genetically modified crops are less likely to produce undesired changes observed in normally bred crops. GMCs result to higher yields for the farmer thus increasing food security; the higher yields necessitate the employment of more workers thus creating employment. Therefore, workers have higher standards of living while improving the economy of a given region. The government is also able to earn more foreign exchange from export of agricultural products. GMCs may be used to combat hunger, particularly in third world countries resulting to fewer deaths and malnutrition caused by lack of adequate food. GMCs have a greater shelf life thus enabling agricultural products to resist spoilage before they reach the market; therefore, they facilitate shipping, particularly long-distance shipping. Some crops are genetically modified to enhance their production of nutrients such as vitamin-enriched corn. GMCs are resistant to abiotic stresses such as drought, nitrogen deficiency and high salinity thus allowing them to mature normally under these conditions. Scientists are exploring the possibility of modifying genes to support salt-tolerant plants that can be used in agriculture. GMCs are also modified to increase their resistance to herbicides allowing farmers to use many herbicides at once to kill weeds that have become resistant to some herbicides. GMCs can also be modified to resist pests resulting to less use of herbicides and pesticides thus farmers can achieve greater efficiency of land. Genetically modified crops can also be used to increase...
References: Actionbioscience.org (2004). Actionbioscience | Ethical Issues in Genetic Engineering and
Transgenics. [online] Retrieved from: http://www.actionbioscience.org/biotech/glenn.html
Agbiosafety.unl.edu (2013). AgBiosafety at UNL - Biotech Basic The Preocess of Plant Genetic
Engineering. [online] Retrieved from: http://agbiosafety.unl.edu/education/summary.htm
Burroughs, T., Knobler, S. & Lederberg, J. (2002). The Emergence of Zoonotic Diseases.
National Academies Press (US)
Chen, Z. (2010). Molecular mechanisms of polyploidy and hybrid vigor. Trends in plant science
15 (2), 57--71.
Gmo-compass.org (2013). Genetically Modified Crops: Soybean, Maize, Rapeseed, Cotton. [online] Retrieved from: http://www.gmocompass.org/eng/grocery_shopping/crops/
Please join StudyMode to read the full document