Cloning is a technique scientists use to make exact genetic copies of living things. Genes, cells, tissues, and even whole animals can all be cloned. Some clones already exist in nature. Single-celled organisms like bacteria make exact copies of themselves each time they reproduce. In humans, identical twins are similar to clones. They share almost the exact same genes. Identical twins are created when a fertilized egg splits in two.
Scientists also make clones in the lab. They often clone genes in order to study and better understand them. To clone a gene, researchers take DNA from a living creature and insert it into a carrier like bacteria or yeast. Every time that carrier reproduces, a new copy of the gene is made.
Animals are cloned in one of two ways. The first is called embryo twinning. Scientists first split an embryo in half. Those two halves are then placed in a mother’s uterus. Each part of the embryo develops into a unique animal, and the two animals share the same genes. The second method is called somatic cell nuclear transfer. Somatic cells are all the cells that make up an organism, but that are not sperm or egg cells. Sperm and egg cells contain only one set of chromosomes, and when they join during fertilization, the mother’s chromosomes merge with the father’s. Somatic cells, on the other hand, already contain two full sets of chromosomes. To make a clone, scientists transfer the DNA from an animal’s somatic cell into an egg cell that has had its nucleus and DNA removed. Continue reading from National Geographic
The idea of human cloning was science fiction when it was first imagined. But in the last few decades, technological and scientific advances have made this a real possibility. Although the ethics of cloning a human are questionable, the technology has led to some promising reproductive and health therapies.
The most basic definition of cloning is the creation of an exact genetic copy of an organism, tissue, cell or gene, according to the U.S. National Library of Medicine. The how and why of cloning really depends on what is being cloned. There are three main types of cloning: Gene cloning, reproductive cloning and therapeutic cloning.
The most commonly applied type of cloning is gene cloning. At its most basic, gene cloning is a biochemical reaction that takes place in every single cell in every organism. It's the creation of a copy of genetic material from an existing strand of genetic material. This natural reaction can be recreated in the lab and is an essential tool for many aspects of biological research.
he most commonly discussed and debated type of cloning is reproductive cloning. This type of cloning creates genetic duplicates of whole organisms from the genetic material of an already-existing organism. A cloned organism is very similar to being an identical twin to the parent organism, just born later.
And perhaps the most medically applicable type of cloning for humans is therapeutic cloning, which creates cloned embryonic stem cells of a patient to create genetically identical cells that can treat a medical condition. "Therapeutic cloning refers to the use of embryonic stem cells that in our lab we derive from somatic cells from a patient's skin," Shoukhrat Mitalipov, an embryologist at Oregon Health & Science University in Portland, told LiveScience in an email. "In our research lab … we can develop [these cells] into different kinds of cells in the body such as neurons or cardiovascular cells." Continue reading from Live Science
