2. There are 3 different types of cloning:
• Gene cloning
• Reproductive cloning
• Therapeutic cloning
3. Gene cloning
• A term used to describe a collection of DNA
fragments derived from the genome of an
organism and cloned randomly into suitable
cloning vectors (plasmids, phages).
• The term genomic DNA clone or
chromosomal DNA clone then refers to an
individual cell carrying a cloning vector with
one of the cellular DNA fragments or to a
phage isolate with a specific DNA insert.
5. Reproductive Cloning
• Reproductive cloning is the production of a genetic
duplicate of an existing organism. A human clone
would be a genetic copy of an existing person.
• Some oppose reproductive cloning because of safety
considerations. Animal cloning is seldom
successful, and many scientists believe that
reproductive cloning can never be made safe. Human
reproductive cloning would also threaten the
psychological well-being of cloned children, open the
door to more powerful genetic manipulation
technologies, and raise other social and ethical
concerns.
6. • Dolly defied scientific convention. With her birth
on 5th July 1996, her makers had done the
impossible - cloned an animal from a cell taken
from an adult mammal.
When Dolly was announced to the world on 22nd
February 1997 she became global front page
news. Press and public flocked to her home at the
Roslin Institute outside Edinburgh to catch a
glimpse of the world's most famous sheep.
8. Therapeutic Cloning
• Which creates embryonic Stem Cells.
Researchers hope to use theses cells to grow
healthy tissue to replace injured or diseased
tissues in the human body.
11. • Advantages of Cloning:
• 1/Potential benefits to modern medicine
Even today, the full potential of stem cells has not been fully explored. The issue of
stem cells has led to controversy because embryos are generally used and they have to
be destroyed for the cells to be used. However, a number of researchers believe that
stem cells will eventually change the face of medicine as we know it. Given the fact
that the cells can be manipulated to mimic other types of cells, this can provide new
ways to treat diseases like cancer and Alzheimer’s.
• Cloning also offers hope to persons needing organ transplants. People requiring organ
transplants to survive an illness often wait years for a suitable donor. In many cases
these patients die waiting, as there are long lists of people requiring organs.
Theoretically, cloning could eliminate this by producing more animals that can act as
suitable donors. Pig livers have been successfully transplanted to human beings, as an
interim measure until a human liver is found. Additionally, cloning of these animals not
put a burden on the world’s food supply.
• 2/Helping infertile couples
Cloning offers couples dealing with fertility the chance to have a child of their own.
Many infertile couples can’t be helped by the techniques currently available. In
fact, although some states have already banned human cloning because of ethical
issues, more couples struggling to have children are starting to consider the
possibilities that cloning offer.
• 3/Reverse the aging process
• Cloning is being touted as a future answer to reverse the effects of aging.The
antiaging market is a prime target becuase it is alreay a multibillion industry.
• 4/Protecting Endangered Species
Despite the best efforts of conservationists worldwide, some species are nearing
extinction. The successful cloning of Dolly represents the first step in protecting
endangered wildlife.
• 5/ Improving food supply
• Cloning could provide a means of cultivating plants that are stronger and more resistant
to diseases, while producing more. The same could happen to livestock as well where
diseases such as foot and mouth disease could be eradicated.Cloning could therefore
effectively solve the world’s food problem and minimize or possible eadicate starvation.
12. • Disadvantages of Cloning
• 1/The Element of Uncertainty
While the cloning of Dolly was seen as a success story, many embryos were
destroyed before the desired result was achieved. The process started with 277
eggs, and Dolly was the single successful outcome. Regardless of success in other
areas, the field of cloning still has a long way to go. Infertile couples for
example, could go through the same heartache as they would if in vitro
fertilization failed.
• 2/Inheriting diseases
Cloning creates a copy of the original. A human clone would therefore inherit the
genetic traits of its predecessor. This includes genetic abnormalities and
diseases. Dolly the sheep for example exhibited signs of what some suggested
were premature aging, although this was firmly denied by her ‘developers’.
• 3/The Potential for Abuse
If human cloning became a reality what checks and balances would be put in place
to prevent abuse? Would scientists go overboard with the technology? If a
couple has a clone that they are not happy with, what would they do next? These
are all questions that must be raised in any discussion on cloning. Some have
expressed the view that clones could be grown in a farm-like fashion simply for
harvesting organs or stem cells. The potential for devaluing human life cannot be
ignored.
• Cloning, like so many other issues that have faced modern science, must be
carefully evaluated. There will always be detractors, those who feel that anyone
involved in cloning is playing God. And this may not be too far from the truth.
However, any discussion on cloning must be looked at in the context of its
inherent value to mankind.
