Главная / Рефераты / Рефераты и топики по иностранным языкам
Топик: The cloning
Notice: Undefined variable: ref_img in /home/area7ru/area7.ru/docs/referat.php on line 323
The cloning The term of cloning came from a Greek word that meant “a branch”, or “a bine”. It has to do chiefly with apprehension of plant cloning. The cloning of plants by stems, bulbs or gemmas has been known for more than 4 thousand years.
Starting from 1970s, for plant cloning the use of small groups of somatic cells and sometimes the use of a single detached cell has been applied.
However, the process of cloning animals has it’s own obstacles. At the time of the animals’ cells development, the cells lose their ability to negotiate the genetic information that lies in the nucleus.
Owing to the experiments on the amphibia in 1950s, the possibility of cloning vertebrates was first shown. These experiments let scientists see that the serial nucleus grafting and “in vitro” cell cultivation in some degree increase the ability of genetic information implementation.
Early in the 90s, the problem of cloning embryonic cells of mammals has been solved. The reconstructed egalitarian of cattle at first are cultivated “in vivo” that is in the corded oviduct of intermediate recipient. Then they are being washed out and transplanted into uterus of the final recipient where their development continues until the cub’s birth time.
In 1997, dr. Williut together with joint authors published a sensational article about successful cloning of a mammal. It was the first time the cloned animal (Dolly) was born as a result of the bank mamma nucleus of fullgrown sheep use. This experiment had a sugnificant defect. There was a very low coefficient of survival (about 0,36%). However, it demonstrates the possibility of full value of obtaining a fullgrown man clone.
The most interesting thing is that the cloning methodology used by Williut had already been elaborated in the former Soviet Union in 1987, but the science academy did not respond to it properly.
Let’s return to the man cloning problem. There are several methods of avoiding the ethical problems. One of them is to grow separate organs from the recipient’s cells. But this seems to be a “cosmic” method.
The real step to immortality is an artificial change of DNA. In June of 2000 an extraordinary event that so many scientists had been waiting for so long has happened. There was an announcement that some scientist from famous Scottish company PPL Therapeutices managed to acquire successful clones of sheep with shifted DNA.
There exists a legal way to avoid the ban on cloning a man which is called a therapeutical cloning of human beings. It’s concerned on creation of early embryos or of a tissue bank for the specific individuals. According to this law a reputed American company “Advanced Cell Technology INC.” (ACT Vooster,MA) declared in November of 2001 a successful human embryo cloning.
Everyone is waiting for the first man clone to come. The sect of raelits is still active. They are convinced in existence of space heralds who have shown the men a door to exponential growth of scientific power and increasing interruption to the natural processes. The sect members don’t even think of concealing that they finance the experiments on human cloning.
In February of 2002 the head of the sect 55 year-old Canadian Claude Varilyon, also known as Rael, declared that “Clonade’s” research on human cloning, suspended by the US government, is being proceeded in the secret laboratories. “….The process is going well. The baby i...
ВНИМАНИЕ!
Текст просматриваемого вами реферата (доклада, курсовой) урезан на треть (33%)!
Чтобы просматривать этот и другие рефераты полностью, авторизуйтесь на сайте:
|
|
|
Добавлено: 2012.03.06
Просмотров: 1716
|
Notice: Undefined offset: 1 in /home/area7ru/area7.ru/docs/linkmanager/links.php on line 21
При использовании материалов сайта, активная ссылка на AREA7.RU обязательная! |
