There are three different types of cloning: recombinant DNA technology (DNA cloning), reproductive cloning, and therapeutic cloning (Cloning). DNA cloning is the transfer of a DNA fragment of one organism to a self-replicating genetic element such as a bacterial plasmid. The DNA fragment can be propagated in a foreign host cell. This technology has been around for about 30 years and is commonly used in molecular biology. Reproductive cloning is a technology used to generate an animal with the same nuclear DNA as another currently or previously existing animal. Dolly was created this way by transferring genetic material from the nucleus of a donor adult cell to an egg which has had its genetic material removed. The reconstructed egg is treated with chemicals or electric current to stimulate cell division, and once the cloned embryo reaches a suitable size, it is transferred to the uterus of a female host to develop until birth. Therapeutic cloning is the production of human embryos for use in research. The goal is not to reproduce a human but to harvest stem cells which can be used to study human development and to treat disease. Stem cells are important because they can be used to generate almost any type of cell in the human body from cells extracted from an egg after it has divided for about five days. The extraction process to recover the cells destroys the embryo, which raises some ethical concerns.
Some people object to cloning on a variety of religious and moral grounds, particularly therapeutic and human cloning, because they believe it is wrong to destroy embryos or interfere with the natural reproductive process (Jeffrey). They label stem cell research as the killing of babies, which is a ridiculous argument when you think that scientists use embryos which are otherwise going to be destroyed. If they are going to be destroyed anyway, why not use them to help cure illness? These embryos are not created just fo...