Name:
Standard: 5c
Objective: Students will be able to explain and describe cloning
Date: Period:
What is Animal Cloning?
Animal Cloning is the process by which an entire organism is reproduced from a single cell taken from the parent organism and in a genetically identical manner. This means the cloned animal is an exact duplicate in every way of its parent; it has the same exact DNA.
Cloning happens quite frequently in nature. Asexual reproduction in certain organisms and the development of twins from a single fertilized egg are both instances of Cloning.
Development of Animal Cloning in the Lab
Scientists have been attempting to clone animals for a very long time. Many of the early attempts came to nothing. The first fairly successful results in animal cloning were seen when tadpoles were cloned from frog embryonic cells. This was done by the process of nuclear transfer. The tadpoles so created did not survive to grown into mature frogs, but it was a major breakthrough nevertheless.
After this, using the process of nuclear transfer on embryonic cells, scientists managed to produce clones of mammals. Again the cloned animals did not live very long. The first successful instance of animal cloning was that of Dolly the Sheep, who not only lived but went on to reproduce herself and naturally. Dolly was created by Ian
Wilmut and his team at the Roslyn Institute in Edinburgh,
Scotland, in 1997. Unlike previous instances, she was not created out of a developing embryonic cell, but from a developed mammary gland cell taken from a full-grown sheep.
Since then Scientists have been successful in producing a variety of other animals like rats, cats, horses, bullocks, pigs, deer, etc. You can even clone human beings now and that has given rise to a whole new ethical debate. Is it okay to duplicate nature to this extent? Is it okay to produce human clones?
What would that do to the fabric of our society?
The Process of Animal Cloning
Initial attempts at artificially induced Animal Cloning were done using developing embryonic cells. The DNA nucleus was extracted from an embryonic cell and implanted into an unfertilized egg, from which the existing nucleus had already been removed. The process of fertilization was simulated by giving an electric shock or by some chemical treatment method. The cells that developed from this artificially induced union were then implanted into host mothers. The cloned animal that resulted had a genetic make-up exactly identical to the genetic make-up of the original cell.

Since Dolly, of course, it is now possible to create clones from non-embryonic cells. Animal cloning can be done both for reproductive and non-reproductive or therapeutic purposes. Cloning is, also, done to produce stem cells or other such cells that can be used for therapeutic purposes, for example, for healing or recreating damaged organs; the intention is not to duplicate the whole organism.
Ethics of Animal Cloning
While most scientists consider the process of animal cloning as a major break through and see many beneficial possibilities in it, many people are uncomfortable with the idea, considering it to be 'against nature' and ethically damning, particularly in the instance of cloning human beings.
The truth is that most of the general public is not aware of the exact details involved in cloning and as a result there are a lot of misconceptions about the entire matter.
In recent times, there has been a spurt of new laws banning or regulating cloning around the world. In some countries, animal cloning is allowed, but not human cloning. Some advocacy groups are seeking to ban therapeutic cloning, even if this could potentially save people from many debilitating illnesses.
Points against Animal Cloning
In a large percentage of cases, the cloning process fails in the course of pregnancy or some sort of birth defects occur, for example, as in a recent case, a calf born with two faces. Sometimes the defects manifest themselves later and kill the clone.
Points for Animal Cloning
On the favorable side with successful animal cloning - particularly cloning from an adult animal - you know exactly how your clone is going to turn out. This becomes especially useful when the whole intention behind cloning is to save a certain endangered species from becoming totally extinct.
Summary Questions
1. What is cloning?__________________________________________________________________________
2. What was the first organism to be cloned?_____________________________________________________________
3. Who is Dolly? ___________________________________________________________________________________
4. What other animals have been cloned?_______________________________________________________________
5. In your opinion, are you in favor or against cloning? Explain your reasons

Cloning: Teacher Notes - Teacher is to use this visual to explain the process of cloning. Students will have copy of this visual without notications.
Diagram of the nuclear transfer procedure that produced the first cloned mammals
In 1997, cloning was revolutionized when Ian Wilmut and his colleagues at the Roslin Institute in Edinburgh,
Scotland, successfully cloned a sheep named Dolly . Dolly was the first cloned mammal.
Wilmut and his colleagues transplanted a nucleus from a mammary gland cell of a Finn Dorsett sheep into the enucleated egg of a Scottish blackface ewe. The nucleus-egg combination was stimulated with electricity to fuse the two and to stimulate cell division. The new cell divided and was placed in the uterus of a blackface ewe to develop. Dolly was born months later.
Dolly was shown to be genetically identical to the Finn Dorsett mammary cells and not to the blackface ewe, which clearly demonstrated that she was a successful clone (it took 276 attempts before the experiment was successful). Dolly has since grown and reproduced several offspring of her own through normal sexual means.
Therefore, Dolly is a viable, healthy clone.
Since Dolly, several university laboratories and companies have used various modifications of the nuclear transfer technique to produce cloned mammals, including cows, pigs, monkeys, mice and Noah

Name:
Place the following steps in the correct order.
Stimulate cell division
Transfer the somatic cell nucleus into the egg cell
Implant embryo into a surrogate mother
Deliver baby
Remove and discard the nucleus from the egg cell
Isolate donor cells from egg donor and germ cell donor
Date: Per.:

Producing Clones: Animal Kingdom
Reproduction
Sexual reproduction involves the merging of two sets of DNA (one from the father's sperm and one from the mother's egg) to produce a new offspring that is genetically different from either parent. Asexual reproduction
(without sex) produces offspring that are genetically identical to the single parent organism.
Plants are not the only organisms that can be cloned naturally. The unfertilized eggs of some animals (small invertebrates, worms, some species of fish, lizards and frogs) can develop into full-grown adults under certain environmental conditions -- usually a chemical stimulus of some kind. This process is called parthenogenesis , and the offspring are clones of the females that laid the eggs.
Another example of natural cloning is identical twins . Although they are genetically different from their parents, identical twins are naturally occurring clones of each other.
Scientists have experimented with animal cloning, but have never been able to stimulate a specialized
(differentiated) cell to produce a new organism directly. Instead, they rely on transplanting the genetic information from a specialized cell into an unfertilized egg cell whose genetic information has been destroyed or physically removed.
In the 1970s, a scientist named John
Gurdon successfully cloned tadpoles. He transplanted the nucleus from a specialized cell of one frog (B) into an unfertilized egg of another frog (A) in which the nucleus had been destroyed by ultraviolet light . The egg with the transplanted nucleus developed into a tadpole that was genetically identical to frog B.
While Gurdon's tadpoles did not survive to grow into adult frogs, his experiment showed that the process of specialization in animal cells was reversible, and his technique of nuclear transfer paved the way for later cloning successes.
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Summary Questions
1. Describe two example of natural cloning.
2. Who successfully cloned a tadpole?
3. What was the importance’s Gurdon’s tadpoles cloning experiment?