Cloning is the process of genetic replication. A clone is a cell similar and identical to the cell from which the clone was derived. There are three types of cloning. Three types of cloning include gene cloning, twinning, and nuclear transfer of genetic material (Clone and Cloning 1 of 4). Cloning should not continue because it can be dangerous for a number of reasons and is not morally or socially appropriate except in cases where it could save the life of a human being. Cloning can involve all kinds of dangers. One type of danger that can result from cloning is medical dangers. The first cloned sheep named Dolly died halfway through the lifespan of a naturally born ewe. She suffered from arthritis and lung cancer (Williams 1 of 2). Cloning can be harmful to many animals. Studies have shown that cloned animals are less healthy than normally bred animals (see 2 of 2). Many cloned animals died prematurely and suffered from age-related illnesses. Cloned mice also have a higher mortality rate due to liver failure and infections (Clone and Cloning 3 of 4). Medical dangers can even arise at birth, such as malformations and abnormalities that can result from cloning (Cohen 51). Another type of danger that can result from cloning is moral danger. Many cloning attempts have been of no use because most of the time they are unsuccessful. Although cloning is common, only four percent of species have been successfully cloned. Most cloning attempts end in failure because cloning mammals is extremely difficult (see 2 of 2). Out of 123 canine surrogates, only three became pregnant, each carrying only one puppy (Brownlee 1 of 2). This shows that cloning is morally dangerous and harms animals unnecessarily. Cloning of humans ...... middle of article ......e Encyclopedia of Sciences June 15, 2011: 4. Web. "Cloning." World of Scientific Discovery 1999: 3. Web.Cohen, Daniel. Cloning. Brookfield, CT: The Millbrook Press, 1998. Print. Grunbaum, Mara. “Back from the Dead: Should Scientists Bring Extinct Species Back to Life?” Science World/Current Science September 2, 2013: 4. Web. Jacqueline Langwith, Ed. Opposing views: cloning. Farmington Hills, MI: Greenhaven Press, Inc., 2012. Print. Kowalski, Kathiann. “Ready, set, clone.” March 2011: 2. Web. Pollack, Andrew. “Cloning is used to create embryonic stem cells.” The New York Times May 16, 2013: 2. Web. See, Kolata G. “Clone.” 1997: 2. Web. Stanley, Debbie. Genetic engineering: the cloning debate. New York, NY: The Rosen Publishing Group, 2000. Print. Williams, Sarah. “Cloning may sound like fiction, but you can clone things right in your own home.” November 2009: 2. Web.