Do You Want to Be Cloned?
The matter of cloning has been much in the news, and there has been considerable controversy over it.
Cloning is not new, however. It is as old as life, and man has known about it as long as he has been cultivating plants. A clone is an organism that has been produced from another organism without the intervention of sex.
A bacterium can divide over and over to produce any number of additional bacteria. All those bacteria are clones of the first. A twig of a tree can be planted, and may develop roots and branches and become a new tree. It is a clone. (In fact, the word "clone" is Greek for "twig.") A starfish can be torn into several pieces, and those may be thrown back into the water.Each piece will then grow into a complete starfish and all will be clones of the original.
The more complex animals do not form clones.They only reproduce sexually. Females produce egg cells and males produce sperm cells; each cell containing a half-set of chromosomes. A sperm and egg combine to form a fertilized egg-cell that contains a whole set of chromosomes, half from the female and half from the male. The fertilized egg-cell then divides and redivides and eventually forms a new organism. Such a new organism, born of sexual combination, has two parents and is not a clone.
Sometimes, though, a fertilized egg divides in two and the two new cells come apart. Each of the separated cells then goes on to divide and redivide and form a whole organism. This can happen in the case of human beings, too, and identical twins result—same sex, same appearance, same chromosomes.Each of the identical twins is the clone of the other.
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Publication information: Book title: The Roving Mind. Contributors: Isaac Asimov - Author. Publisher: Prometheus Books. Place of publication: Amherst, NY. Publication year: 1997. Page number: 251.