The mutations were collected, and the inheritance of these mutations were analyzed. But these mutations clearly represent only a small number of all possible mutations. To genetically dissect a biological system further, new mutations were created by scient ists by treating an organism with a mutagenizing agent. These mutations are called induced mutations . The spontaneous mutation rate varies.
Large gene provide a large target and tend to mutate more frequently.
Given that the human genome contains 100,000 genes, we can conclude that we would predict that 1-5 human gametes would contain a mutation in some gene. Mutations can be induced by several methods. The three general approaches used to generate mutations are radiation , chemical and transposon insertion . The first induced mutations were created by treating Drosophila with X-rays. Using this a pproach Mueller to induce lethal mutations.