Genetically Modified Food?
What are genetically modified organisms, and why are they in our food?
The question of what is and is not a "genetically modified organism" (GMO) might be a little more difficult to answer than you first think. Let's begin by defining different types of genetic modification.
What are genetically modified organisms, and why are they in our food?
Breeding: This is when people select plants or animals with specific qualities, then they select which ones will produce offspring. By doing this for several generations people can manipulate many traits within the species such as its size, growth rate, or how it tastes. Since the advent of agriculture people have been genetically manipulating the food supply through breeding practices.
What are genetically modified organisms, and why are they in our food?
Crossing: Similar to breeding, this process involves taking two similar organism and mixing them. This is often done with plants such as tomotoes. Two varieties that have desirable qualities when put together are crossed to make a first generation cross (F1). However, with crossing unlike breeding the following generations may not carry the desirable qualities of F1, so instead of having a new "better" species you need to go back to the original plants and cross them again.
What are genetically modified organisms, and why are they in our food?
Transgene addition: This is what most people mean when they speak of GMOs. A transgene is a gene from one organism directly inserted into the genome of another organism. This tool has been used to introduce a nutrient into a food that is lacking in it, and to increase a plant's resistance to certain pests. This is the most targeted way to genetically alter a plant or animal to have desired qualities.
What are genetically modified organisms, and why are they in our food?
So, why are GMOs in our food? The answer is in the descriptions of the GMO types above. Since people started growing food instead of collecting it, they have worked to increase crop yields, make the foods taste better, grow faster, resist pests, and resist harsh weather conditions such as drought. In the past this has been done by breeding and selecting plants and animals that seemed better suited to our needs and the local environment. Now, we are more directly manipulating plant and animal genomes to make organisms that have very specific new capabilities and qualities. This is where the GMO controversy begins.
What are genetically modified organisms, and why are they in our food?
Transgenic GMOs are controversial mainly because a gene from one organism is introduced into another, and the long-term effects of this type genetic manipulation are unknown. We do not know if the gene we are introducing will stay in the target organism, or if it will jump species and enter wild plants or animals. We do not know how the transgene will affect the food we eat.
About the site:
I developed geneticsalive.com as a companion website to cellsalive.com.
Everything a cell does is a direct result of the genetics of that cell,
whether it is a single-cell organism or part of a much larger organism.
Thus, understanding the cells requires an understanding of the basis of
all of their behaviors.
About the author:
I am a microbiologist studying microbial pathogenesis and the host
immune response. My studies have included work in many pathogens
including Rabies and Influenza viruses, Mycobacterium tuberculosis,
Francisella tularensis, and Salmonella enterica. I currently live just
outside of Philadelphia, PA, where I work as a postdoctoral fellow
researching antigen processing and presentation during rabies
infection.
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