Cloning :: essays research papers

Cloning  Ã‚  Ã‚  Ã‚  Ã‚   What is a Clone? A clone is a group of genetically identical cells. For example, tumors are clones of cells inside an organism because they consist of many replicas of one mutated cell. Another type of clone occurs inside a cell. Such a clone is made up of groups of identical structures that contain genetic material, such as mitochondria and chloroplasts. Some of these structures, called plasmids, are found in some bacteria and yeasts. Techniques of genetic engineering enable scientists to combine an animal or plant gene with a bacterial or yeast plasmid. By cloning such a plasmid, geneticists can produce many identical copies of the gene. Uses of Cloning:   Ã‚  Ã‚  Ã‚  Ã‚  Researchers said the cloning of animals, especially those that have been genetically modified in certain ways, could have a number of medical, agricultural, and industrial applications. For example, cloning could result in the mass production of genetically modified cattle that secrete valuable drugs into their milk. But the cloning of animals indicated that it might also be possible to clone humans. Much of the public expressed revulsion toward the prospect of human cloning, and some politicians vowed to outlaw it. Its proponents, however, saw human cloning as a way to help people, such as by allowing infertile couples to have children. Early Scientific Experiments of Cloning: Scientists have long been intrigued by the possibility of artificially cloning animals. In fact, people have known since ancient times that just just cutting them into two pieces can clone some invertebrates, such as earthworms and starfish. Each piece grows into a complete organism. The cloning of vertebrates (animals with back bones) is much more difficult to clone. The first step in the cloning the complex organisms (vertebrates) came in the 1950's with experiments done on frogs.   Ã‚  Ã‚  Ã‚  Ã‚  In 1952, Robert Briggs and Thomas King, biologists at the Institute for Cancer Research (now the Fox Chase Cancer Center) in Philadelphia, developed a cloning method called nuclear transplantation, or nuclear transfer, which was first proposed in 1938 by the German scientist Hans Spemann. In this method, the nucleus--the cellular structure that contains most of the genetic material and that controls growth and development--is removed from an egg cell of an organism, a procedure known as enucleation. The nucleus from a body cell of another organism of the same species is then placed into the enucleated egg cell. Nurtured by the nutrients in the remaining part of the egg cell, an embryo (an organism prior to birth) begins growing. Cloning :: essays research papers Cloning  Ã‚  Ã‚  Ã‚  Ã‚   What is a Clone? A clone is a group of genetically identical cells. For example, tumors are clones of cells inside an organism because they consist of many replicas of one mutated cell. Another type of clone occurs inside a cell. Such a clone is made up of groups of identical structures that contain genetic material, such as mitochondria and chloroplasts. Some of these structures, called plasmids, are found in some bacteria and yeasts. Techniques of genetic engineering enable scientists to combine an animal or plant gene with a bacterial or yeast plasmid. By cloning such a plasmid, geneticists can produce many identical copies of the gene. Uses of Cloning:   Ã‚  Ã‚  Ã‚  Ã‚  Researchers said the cloning of animals, especially those that have been genetically modified in certain ways, could have a number of medical, agricultural, and industrial applications. For example, cloning could result in the mass production of genetically modified cattle that secrete valuable drugs into their milk. But the cloning of animals indicated that it might also be possible to clone humans. Much of the public expressed revulsion toward the prospect of human cloning, and some politicians vowed to outlaw it. Its proponents, however, saw human cloning as a way to help people, such as by allowing infertile couples to have children. Early Scientific Experiments of Cloning: Scientists have long been intrigued by the possibility of artificially cloning animals. In fact, people have known since ancient times that just just cutting them into two pieces can clone some invertebrates, such as earthworms and starfish. Each piece grows into a complete organism. The cloning of vertebrates (animals with back bones) is much more difficult to clone. The first step in the cloning the complex organisms (vertebrates) came in the 1950's with experiments done on frogs.   Ã‚  Ã‚  Ã‚  Ã‚  In 1952, Robert Briggs and Thomas King, biologists at the Institute for Cancer Research (now the Fox Chase Cancer Center) in Philadelphia, developed a cloning method called nuclear transplantation, or nuclear transfer, which was first proposed in 1938 by the German scientist Hans Spemann. In this method, the nucleus--the cellular structure that contains most of the genetic material and that controls growth and development--is removed from an egg cell of an organism, a procedure known as enucleation. The nucleus from a body cell of another organism of the same species is then placed into the enucleated egg cell. Nurtured by the nutrients in the remaining part of the egg cell, an embryo (an organism prior to birth) begins growing.