4 стр.
Формат файла
.html — Html-документ
315225.zip — 3.04 kb
Оцените работу
Хорошо  или  Плохо

Текст работы

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

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.

Ваше мнение