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Advantages and Disadvantages of Cloning
Genetically Modified Foods
Stem Cell Research
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Advantages and Disadvantages of Cloning
What is it?
What exactly is cloning?
Cloning is the creation of an organism that is an exact genetic copy of another. This means that every single bit of DNA is the same between the two!
You might not believe it, but there are human clones among us right now. They weren't made in a lab, though: they're identical twins, created naturally. Below, we'll see how natural identical twins relate to modern cloning technologies.
1. Artificial Embryo Twinning
Artificial embryo twinning is the relatively low-tech version of cloning. As the name suggests, this technology mimics the natural process of creating identical twins.
In nature, twins occur just after fertilization of an egg cell by a sperm cell. In rare cases, when the resulting fertilized egg, called a zygote, tries to divide into a two-celled embryo, the two cells separate. Each cell continues dividing on its own, ultimately developing into a separate individual within the mother. Since the two cells came from the same zygote, the resulting individuals are genetically identical.
Artificial embryo twinning uses the same approach, but it occurs in a Petri dish instead of in the mother's body. This is accomplished by manually separating a very early embryo into individual cells, and then allowing each cell to divide and develop on its own. The resulting embryos are placed into a surrogate mother, where they are carried to term and delivered. Again, since all the embryos came from the same zygote, they are genetically identical.
2. Somatic Cell Nuclear Transfer
Somatic cell nuclear transfer, (SCNT) uses a different approach than artificial embryo twinning, but it produces the same result: an exact clone, or genetic copy, of an individual. This was the method used to create Dolly the Sheep.
What does SCNT mean? Let's take it apart:
: A somatic cell is any cell in the body other than the two types of reproductive cells, sperm and egg. Sperm and egg are also called germ cells. In mammals, every somatic cell has two complete sets of chromosomes, whereas the germ cells only have one complete set.
: The nucleus is like the cell's brain. It's an enclosed compartment that contains all the information that cells need to form an organism. This information comes in the form of DNA. It's the differences in our DNA that make each of us unique.
: Moving an object from one place to another.
To make Dolly, researchers isolated a
from an adult female sheep. Next, they
from that cell to an egg cell from which the nucleus had been removed. After a couple of chemical tweaks, the egg cell, with its new nucleus, was behaving just like a freshly fertilized zygote. It developed into an embryo, which was implanted into a surrogate mother and carried to term.
The lamb, Dolly, was an exact genetic replica of the adult female sheep that donated the somatic cell nucleus to the egg. She was the first-ever mammal to be cloned from an adult somatic cell.
How does SCNT differ from the natural way of making an embryo?
The fertilization of an egg by a sperm and the SCNT cloning method both result in the same thing: a dividing ball of cells, called an embryo. So what exactly is the difference between these methods?
An embryo is composed of cells that contain two complete sets of chromosomes. The difference between fertilization and SCNT lies in where those two sets originated.
In fertilization, the sperm and egg both contain one set of chromosomes. When the sperm and egg join, the resulting zygote ends up with two sets - one from the father (sperm) and one from the mother (egg).
In SCNT, the egg cell's single set of chromosomes is removed. It is replaced by the nucleus from a somatic cell, which already contains two complete sets of chromosomes. Therefore, in the resulting embryo, both sets of chromosomes come from the somatic cell.
What used to be science fiction is now turning into reality. Artificial cloning is happening and will definitely be a part of this generation's future. Scientists are creating a clone by imitating the process in which identical twins are created. Even though it is a cloning is a similar process, it is different from a natural identical twin.
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
used and they have to be destroyed for the cells to be used. However, a
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
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
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.
Helping infertile couples
Cloning offers couples dealing with
the chance to have a child of their own. Many infertile couples can’t be helped by the
currently available. In fact, although some states have already banned human cloning because of ethical issues, more couples struggling to have
are starting to consider the possibilities that cloning offer.
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.
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.
Improving food supply
Cloning could provide a means of cultivating
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.
The improvement of reconstructive and cosmetic surgery
Reconstructive and cosmetic surgery could be improved with the help of cloning. Up to today cosmetic surgery can be risky because the used materials are foreign to the body. Silicone breast implants may cause immune disease, for example. Doctors would have the ability to manufacture bone, fat and connective tissue that matches the patient′s tissues exactly. Every person could change his appearance riskless.
4.3 The chance to have children for infertile couples
Cloning could help infertile couples if they want to have children. At the moment those couples have a harsh time. They have to "go through physically and emotionally painful procedures"10 which are not only expensive and take a lot of time but which are also "estimated to be less than 10 % succsessful"11. Current infertility treatments don′t seem to improve soon because "being infertile is not considered a `real medical problem′ "12 in people′s attitudes.
The solution is called "in vitro fertilization": One single egg cell has to be taken from the woman′s ovary and put into a dish where it is fertilized with a sperm cell of the man. The fertilized egg cell is than placed into the woman′s womb. It′s guaranteed that this technique is successful.
Seen from the couples point of view using cloning in order to have children is a brilliant idea but what about the ethical views? Cloning children will probably lead to the designer baby since the fertilized egg cell ( which is to be an embryo soon ) could also be enhanced with extra genes for special traits such as musical or athletic talent.
Furthermore the egg cell could be tested for special heriditary diseases. If they don′t excist, the egg cell can be implanted into the woman′s womb, otherwise it will be annihilated. This technique is called pre-implantation genetic diagnosis (pgd).
Maybe the parents want only a boy or a girl. Then, using a procedure called sexing, scientists separate the sperm cells and choose the sex of the planned child.
There are several critical points that have to be considered when talking about those embryo selecting techniques13:
One of the main advantages of cloning is for infertile couples to be able to reproduce, but there are other methods and in the worst of the cases they could adopt a child since the worlds is already overpopulated. These children would be genetically modified to fit what the parents want so it would apeal to many othres. In the long run humans naturally born would be considered inferior since the genes of the clones can be manipulated converting the birth of a new child in a race of who can produce the best one by societie's standards. Another main apeal of cloning is that stem cells of cloned embroyos could be helpfull to cure many deseases. What has to be considered is that these embroyos are a baby in the eariest stages of growth. By extracting the stem cells of these embroyos one is killing a potential life.Thbough othr benefits could be benefitial to society, like producing more food there would have to be tests conducted to be positive theat these products will not have any undesired efects. Cloning may have some advantages but the results are uncertain and the negative implications affecting the natural birth and health of humans by far surpass the adavtages that cloning may have.
Losing the diversity of genes
Human can live on the Earth relies on the diversity of genes. And the diversity of genes comes from parents having different sets of genes. The most horrendous part of identical genes is that it will weaken our power and adaptations, which make us subjected to great diseases easily. In addition, human cloning is just copying the identical genes, which means it will decrease the diversity of genes.
Furthermore, the beauty of humanity lies in the differences we see in each other. Cloning would eliminate surprise and predict expectancy.
The great diseases and leading to extinction
As mentioned above, in human cloning, all human beings will be identical. Which means that entire human is at a risk of getting infected by the same type of pathogen. In scientific point of view, if every one has the same type of genes and they are closed to each other they may not defend against the same kind of serious disease. Then cloning will be detrimental in terms of a great disaster.
Another negative effect of cloning is inbreeding, as everyone has the same genotype and keep reproducing among themselves. This would lead us to our own extinction finally.
Richard Nicholson of the British Bulletin of Medical Ethics said that cloning research may well be “sowing the seeds of our own destruction.”
evastate parenting and family life
The basic concept of a family is a couple falls in love and determines to care each other. Then the couple may decide to have children which they will love them dearly. But parents of clones might value their children according to how much they look like to themselves. Cloning, at a result, undermine the basic elements of loving, nurturing family and to accept each child as an unique individual.
Cause unbalance to the society
Cloning may arouse social side effects. It is ridiculous that reproduction is separated from love and other human relationship. The entire world may use cloning for eugenics that would lead to efforts to selectively breed children who are of more intelligent, heavier and extraordinary.
Even though cloning may have useful advantages, humans must never allow this to happen because of its terrible consequences. Apart from causing the loss of diversity in genes, eventually leading us to extinction, people would compete for the perfect child and they would never be happy. Love from parents to children would disappear because it isn’t the same having a cloned baby than a normal baby, which is unique and much more appreciated because of its value. Human’s value would be undermined to the point in which they could be sold. Human cloning be the worst error in human history and we must all be against it avoiding it to happen.
Example of Cloning
Dolly the Sheep, most famous cloned animal in the world
Although the word cloning might only give us images of humans, it is most commonly tried on animals. Dolly the sheep is the most famous cloned animal in the world, since her birth was announced in 1997.
Back in 97, scientists were just starting to experiment cloning and used several animals during the process. Scientists basically wanted to experiment nuclear transfer and used the somatic cell of an adult sheep to create Dolly.
The nuclear transfer worked in the following way:
The cell used as the donor for the cloning of Dolly was taken from a mammary gland, and the production of a healthy clone therefore proved that a cell taken from a specific part of the body could recreate a whole individual. As Dolly was cloned from part of a mammary gland, she was named after the famously curvaceous country western singer Dolly Parton."
Creation of Dolly:
Creation process of Dolly.
"Dolly was created using the technique of somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilised oocyte (developing egg cell) that has had its nucleus removed. The hybrid cell is then stimulated to divide by an electric shock, and when it develops into a blastocyst it is implanted in a surrogate mother.
Dolly was the first clone produced from a cell taken from an adult mammal. The production of Dolly showed that genes in the nucleus of such a mature differentiated somatic cell are still capable of reverting back to an embryonictotipotent state, creating a cell that can then go on to develop into any part of an animal".
Was Dolly able to reproduce as a clone? The answer is yes! When Dolly was born she was immediately put in the Roslin Institute in Edingburgh where she spent her 6 years of life. There she was bred with another lamb and together they produced 6 lambs in total. The first lamb Dolly produced was Bonnie, in 1998. A year later Bonnie produced twin lambs, Sally and Rosie. Finally in 2000, Dolly gave birth to triplets
Lucy, Darcy and Cotton.
In 2003, Dolly developed a severe case of arthritis and lung disease. Although her life expectancy was that of 12 years, she only lived until she was 6. Scientists have researched on whether her short life spam had anything to do with her being a clone and surprisingly it wasn't what made Dolly's life so short. The lung disease Dolly had developed was fairly common in sheep and a sheep form the same flock had died from the same type of lung disease, retrovirus JSRV.
Nevertheless, some researches do believe that "a
contributing factor to Dolly's death was that she could have been born with a genetic age of six years, the same age as the sheep from which she was cloned. One basis for this idea was the finding that Dolly's telomeres were short, which typically is a result of the ageing process.
The cloning of Dolly catalyzed the cloning of severals other mammals like horses and bulls. Through deep experimentation, cloning became more successful and cloned animals started living more normally. Although cloning in animals is becoming more known and successful, Wilmut, the creator of Dolly believes that "the
nuclear transfer technique may never be sufficiently efficient for use in humans."
Comment Anandan Amirthanayagam:
I agree entirely, perfect children would be being manufactured and have severe advan
tages over natural children throughout their lifetime. This entire subject reminds me strongly of the film "Gattica" which takes place in a world where all that matters about you is the genetic makeup. This is a scary prospective that could become reality in many ways.
Comment Andrea Garrido-Lecca:
I feel that cloning should not take place because every single person or animal on earth should have their own genetic information. Also I feel that animals and humans should not be experimented and tested. As mentioned above in the sheep's, Dolly, example, "a
contributing factor to Dolly's death was that she could have been born with a genetic age of six years, the same age as the sheep from which she was cloned...". I think it is not fair how their life spam is shorter and how many people think that it was because of genetic age of the original sheep. In my opinion everybody should have the right to live with their own original genetic information and not live an experiment.
Comment: Harshita Malhotra
Wow this article has amazing information. I've learned a lot from it. It is amazing how people actually want to be so perfect and a like, it is our differences that make us special. In my opinion cloning should not be encouraged at all and there is already such a huge population in the world why increase it more to increase the world's problems.
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