How it works
To clone an animal in a lab a scientist must extract the nucleus from a donor cell. There also has to be an enucleated cell from another donor. The scientist will then fuse the cell and enucleated egg with electricity. The egg fused with a cell will then turn into an embryo. The embryo will then be implanted into the donor of the nucleus which will then go on to give birth to an exact replica of the donor of the egg cell. This usually takes hundreds of attempts.
This evidence tells us that cloning is a very complicated procedure which requires patience. It is also very expensive which needs millions of pounds worth of equipment and can take years.
Evaluating human cloning
Human cloning is the creation of a genetically identical copy of an existing or previously existing human. The term is generally used to refer to artificial human cloning; human clones in the form of identical twins are common, with their cloning occurring during the natural process of reproduction. There are two commonly discussed types of human cloning: therapeutic cloning and reproductive cloning. A third type of cloning called replacement cloning exists in theory, and is a combination of therapeutic and reproductive cloning. Replacement cloning entails the replacement of an extensively damaged, failed, or failing body through cloning followed by whole or partial brain transplant. It has been proposed as a way to greatly extend lifespan.
Human cloning is a very controversial topic with many organizations wanting to ban research completely. Some people and groups oppose therapeutic cloning but many more oppose reproductive cloning.
Serious ethical issues have arisen in discussions of harvesting of organs from clones. Some people have considered the idea of growing organs separately from a human organism - in doing this, a new organ supply could be established without the moral implications of harvesting them from human organisms. Research is also being done on the idea of growing organs that are biologically acceptable to the human body inside of other organisms, such as pigs or cows, then transplanting them to humans.
Cloning endangered species?
In a 2006 review, Dr.David Ehrenfeld concludes:
“Vertebrate cloning poses little risk to the environment, but it can consume scarce conservation resources, and its chances of success in preserving species seem poor. To date, the conservation benefits of transgenics and vertebrate cloning remain entirely theoretical, but many of the risks are known and documented. Conservation biologists should devote their research and energies to the established methods of conservation, none of which require transgenics or vertebrate cloning.”
This means that there is a very slim chance of achieving this due to the fact that there are high risks and can consume valuable resources that could be useful in other experiments. Also in trying to clone an endangered species of animal, tests would have to be done on the animal itself which could put it at risk and add to the possible extinction.
Plant cloning
Natural cloning has been going on for billions of years. For example, when a strawberry plant sends out a runner (a form of modified stem), a new plant grows where the runner takes root. The new plant is a clone and is identical to its parent. Similar cloning takes place in grass, potatoes and onions. Humans have been cloning plants in various ways for thousands of years. When a leaf cutting is taken to grow a new plant, which is called vegetative propagation, you are cloning the plant because it has the same genetic make up as the donor plant.
Though plant cloning is mostly viewed as a very useful way of reproducing plants there are various factors that can go wrong as well.
In the table below I have portrayed the pros and cons of plant cloning.
Cloning of plants has many important commercial implications. Successful varieties of plants can be produced commercially on a massive scale in a relatively short space of time, enabling scientists to develop:
- fast growing crops that give more than one harvest in a year, or
- Crops with better disease-resistant qualities.
Animal cloning
Like plants some animals can be cloned naturally. The unspecialized eggs of some animals such as worms and some types of fish, frogs and lizards can grow into fully formed adults under the right conditions. The offspring are clones of the female who laid the eggs.
Another example of natural animal cloning is identical twins. Even though they are genetically different to their parents, they are naturally occurring clones of each other. Artificial cloning of animals is now commonplace in laboratories. The most famous example of animal cloning is Dolly the Sheep, born in the UK in 1997 using a technique called cell transferring.
This is the method:
- An egg cell was removed from the ovary of an adult female sheep, and the nucleus removed.
- Using micro-surgical techniques, the empty egg cell was fused with DNA extracted from an udder cell of a donor sheep
- The fused cell now began to develop normally, using the donated DNA.
- Before the dividing cells became specialised the embryo was implanted into the uterus of a foster-mother sheep. The result was Dolly, genetically identical to the donor sheep.
I will now display the advantages and disadvantages of animal cloning.
If possible it could be very useful to be able to clone animals they could provide extra food and could help find cures for diseases and further the research of medicines and vaccines.
Who and why to clone?
Not all cloning would mean to create an entirely new human being. Cloning is seen as a possibility to cure some people’s severe medical problems.
Scientists could clone our genes and fix mutated cells which cause diseases. In January 2001, the British government passed rules to allow cloning of human embryos to combat diseases such as Parkinson's and Alzheimer's.
As it may take time for cloning to be fully accepted, as some people see it as unnatural and other religious reasons, therapeutic cloning may be the first step in that direction. Therapeutic cloning is the process by which a person's DNA is used to grow an embryonic clone. However, instead of inserting this embryo into a surrogate mother, its cells are used to grow stem cells. These stem cells can be used as a human repair kit. They can grow replacement organs, such as hearts, livers and skin. They can also be used to grow neurons to cure those who suffer from Alzheimer's, Parkinson's or Rett Syndrome.
Some people may see cloning as a way to treat couples fertility problems. This could be used for couples who can’t have children but want the child to have genes from at leas one of the parents. This procedure would involve injecting cells from an infertile male into an egg, which would be inserted into the female's uterus. Their child would look the same as the father.
Another possibility could be to clone dead relatives such as parents, grandparents etc. using their DNA. In theory this could mean that you could be the parent of your grandmother or even your own parents. However this would be viewed as socially, morally and ethically wrong. Although it is a door which could soon be opened. One American couple has already paid $500,000 to a company called Clonaid to clone there deceased infant daughter using preserved skin cells. Although there are laws in America and Europe that bans cloning of humans and animals, in many countries these laws do not apply. And so it would be legal to do so.
Just because we can, does it mean we should?
The closer we get to being able to clone a healthy human being, the hotter the debate over it grows. Just because we have the technology and the facilities to clone a human, does it mean this is the right thing to do? There are certain laws against it. In America it has not been completely banned, yet most states have passed laws against it. also anyone in the united states must have official permission before attempting any type of cloning. In Japan it is strictly illegal and can be punishable by up to 10 years in jail. England has allowed cloning human embryos but is working on an authorisation banning total human cloning.
Laws are one thing but some scientists believe that the technology is not ready to be tested on humans. Cloning technology is still in the very early stages and 98% of cloning attempts end in failure. The embryos are either not suitable for planting into the uterus or they die shortly after birth.
The clones that do survive often suffer from genetic abnormalities after their birth. Some clones have been born with defective hearts, lung problems, diabetes, blood vessel problems and malfunctioning immune systems.
Cloning is one of the biggest advances in science in human history but as the technology and research continues, it could be one of the biggest ethical dilemmas of the 21st- century.
The human clone (if it was achieved)
If a human clone did take place we would have to look at life from its point of view. We know very little about the long term affects of the human clone. There is evidence that it may not live as long as the average human being and it may suffer from physical or mental health problems. There is also a debate of whether the human would look exactly like its parents. Genetically the clone would be 99.9% identical to its parents but it would not be exactly the same because there are some important genes that come from the egg donor. Also the clone would be subject to environmental factors and a different up-bringing to its genetic parents which could result in a different appearance and attitude to the genetic parent.
There is also the matter of whether the clone would fit into a normal society. There may be certain groups or organisations which a strongly against human cloning and think that the clone would not have a right to life which might try to destroy the clone. This would not be fair on the clone as it did not decide to be created in the way it was. It may also be unfair on the scientists which created it.
Conclusion
I think that one day, if necessary, cloning should be allowed. I think that cloning stem cells to cure disabilities and diseases should definitely be allowed as it save millions of lives and cure many people. It is also evident that complete human cloning may not be possible for a number of years and even when it is possible there may be protest to whether it should actually be done.
Also there is the matter of the law and the possibility of a black market of human cloning which would be highly illegal and could be disastrous for society. We need to think about the advantages and disadvantages of human cloning and the economical and ethical cost. Alternatively the cloning of animals such as fish, pigs and cattle may be vital to combat world hunger or if any animal holds the cure to a certain disease it could be mass produced although we would have to look at the factors of if it would be cruel to harvest and manufacture animals for there resources.
Overall I think that therapeutic cloning should take place as it may be the key to the world’s deadliest diseases and vital to new medicines and cures.
Human cloning itself I think should not take place as there is no real reason to do so and just because we can some things should be left undone.
Evaluation
I think that this case study has been successful in showing the various forms, techniques and ideas of cloning. I have explored the scientific nature of cloning referring to facts, figures and statistics to back up my evidence. I have also shown the ethical controversy which is strongly linked to cloning and explained this carefully.
I have spoken in a continuous tone throughout the investigation while keeping precise and to the point instead of jumping around different topics and going off the point of the task in hand.
Some things that could be improved on in this case study are data display. I could have included more graphs or charts. I also could have explored the nature of cloning in greater depth, looking at the chemicals and equipment used to make cloning possible.
Bibliography