So, these types of natural g mutations that take place as a result of one of the many natural processes that exist in the cell is known as a spontaneous mutation. Now, on the other hand, a gene mutation can also take place as a result of one or more physical or chemical agents known as mutagens. So these are basically outside physical or chemical forces that can basically induce our g mutation. And one example is UV radiation. So, UV radiation is an outside physical agent that can basically cause harm and create a gene mutation in DNA. So we have induced mutations or spontaneous mutations.