Saturday, August 24, 2019

Genetically Modified Crops Essay Example | Topics and Well Written Essays - 1000 words

Genetically Modified Crops - Essay Example The resultant organism would be referred to as transgenic. Similarly, genetically modified, GM crops would be created by changing the genetic material of crops though biotechnology. Techniques Various techniques have been used to introduce the needed genes in crops or inactivate the undesired ones. Bacterium Agrobacterium has the capacity to infect plants hence has been used as an appropriate DNA carrier. Its preparation would be conducted in a specialised solution that would make its cell walls even more porous. The desired gene would then be inserted into the plasmid of the bacterium – its extra chromosomal DNA molecule – and then dropped into the solution which would be heated to allow the plasmid to enter into the bacterium and express a new gene. The altered bacterium referred to as recombinant would be left to recover before being allowed to grow and probably make copies of the new gene. The bacterium would then be exposed to plant cells to deliver the new gene an d plasmid to the cells targeted for transformation (Adugna & Mesfin 2). With gene slicing, the restriction enzymes of bacteria would be used to attack foreign DNA, cutting it into accurate sections inhibiting it from insertion into the chromosome of the bacteria. Different bacteria produce varied restriction enzymes which cut DNA at different places. Molecular biologists use this capability to genetically engineer the DNA to be inserted into target cells for genetic modification. Another enzyme, DNA ligase, would then be used to fuse the sequences of the new gene into the chromosome. Alternatively, the new gene could be introduced into the bacterium’s plasmid which would invade the cell being targeted and deliver the gene. Carter, Moschini and Sheldon (15) give Agrobacterium tumefaciens as an example in this category. Other techniques include biolistics where the selected DNA would be attached to gold or tungsten microscopic particles and fired into the target cells by use of gas under pressure. In lipofection, liposomes would be used to carry the selected DNA and would be placed together with the target cells in a special solution causing a merger between the liposomes and phospholipids from the cell membrane giving in to the entry of the DNA into the chromosome. The viral carriers technique would involve use of a virus whose genetic make-up has the selected DNA added onto it to invade the target cells without causing death or damage thus adding the desired DNA to the target cells. In calcium phosphate precipitation, the selected DNA would be introduced to calcium phosphate creating tiny granules that would have the target cells respond by surrounding and ingesting the granules – endoocytosis – thus causing the granules to release the DNA into the host chromosomes. Examples of GM crops There are soybeans that have been modified genetically so as to make them tolerant to high levels of herbicides that could kill them, making them herbicide tolerant, HT. There are other crops including maize and cotton that have been engineered genetically to resist particular insect pests such as the toxin genes, Bt toxin extracted from Bacillus thuringiensis found in soil and introduced into the DNA of crops so as to make the crops produce specific toxins that kill the larvae of insect pests (Carter, Moschini & Sheldon 7). This would make such crops insect resistant, IR. The

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