The DNA content of the cell must accurately replicate itself prior to mitosis or meiosis. Given the complexity of the DNA molecule and the vast number of cell divisions that take place with in the life time of a multi cellular organism, it is obvious that copying errors are likely to occurs. If unrepaired such errors change the linear order of the DNA bases and produce mutation in genetic code. Many mutations arise from unknown causes. These are perhaps due to fruition (rise) of karma of individual organism. In addition to these so-called spontaneous mutations, researchers have demonstrated that a variety of environmental agents including ionizing radiation, toxic chemicals and certain viruses can induce mutations.[35]
Footnotes