Калужские рефераты


Дипломы, курсовые и рефераты на иностранных языках

Скачать реферат:

Название: Genetic Engineering

  1     2    3    4    5    6    7    8  

All that we are is the result of what we have thought
Buddha
For what shall it profit a man, if he shall gain
the whole world and lose his own soul?
The Bible
Introduction
While plant biotechnology has been used for centuries to enhance plants, microorganisms and animals for food, only recently has it allowed for the transfer of genes from one organism to another. Yet there is now a widespread controversy over the harmful and beneficial effects of genetic engineering to which, at this time, there seems to be no concrete solution. The ideas below are expected to bring in a bit of clearance into the topic. Here I'm going to reveal some facts concerning genetic engineering, specially the technology, its weak and strong points (if any). Probably the information brought is a bit too prejudiced, for I'm certainly not in favor of making jokes with nature, but I really tried to find some good things about GE.
What is genetic engineering?
Genetic engineering is a laboratory technique used by scientists to change the DNA of living organisms.
DNA is the blueprint for the individuality of an organism. The organism relies upon the information stored in its DNA for the management of every biochemical process. The life, growth and unique features of the organism depend on its DNA. The segments of DNA which have been associated with specific features or functions of an organism are called genes.
Molecular biologists have discovered many enzymes which change the structure of DNA in living organisms. Some of these enzymes can cut and join strands of DNA. Using such enzymes, scientists learned to cut specific genes from DNA and to build customized DNA using these genes. They also learned about vectors, strands of DNA such as viruses, which can infect a cell and insert themselves into its DNA.
With this knowledge, scientists started to build vectors which incorporated genes of their choosing and used the new vectors to insert these genes into the DNA of living organisms. Genetic engineers believe they can improve the foods we eat by doing this. For example, tomatoes are sensitive to frost. This shortens their growing season. Fish, on the other hand, survive in very cold water. Scientists identified a particular gene which enables a flounder to resist cold and used the technology of genetic engineering to insert this 'anti-freeze' gene into a tomato. This makes it possible to extend the growing season of the tomato.
At first glance, this might look exciting to some people. Deeper consideration reveals serious dangers.
Techniques
There are 4 types of genetic engineering which consist of recombinant engineering, microinjection, electro and chemical poration, and also bioballistics.
r-DNA technology
The first of the 4, recombinant engineering, is also known as r-DNA technology. This technology relies on biological vectors such as plasmids and viruses to carry foreign genes into cells. The plasmids are small circular pieces of genetic material found in bacteria that can cross species boundaries. These circular pieces can be broken, which results with an addition of a new genetic material to the broken plasmids. The plasmids, now joined with the new genetic material, can move across microbial cell boundaries and place the new genetic material next to the bacterium's own genes. After this takes place, the bacteria will then take up the gene and will begin to produce the protein for which the gene codes. In this technique, the viruses also act as vectors. They are infectious particles that contain genetic material to which a new gene can be added. Viruses carry the new gene into a recipient cell driving the process of infecting that cell. However, the viruses can be disabled so that when it carries a new gene into a cell, it cannot make the cell reproduce or make copies of the virus.

  1     2    3    4    5    6    7    8  

Скачан: 1 раз.

Скачать диплом, курсовую, реферат, контрольную

Понравилось? тогда жми кнопку!

Лучшие студенческие анекдоты

Поиск


Реклама

загрузка...