Point mutations are often caused by substances called mutagens explain?

Point mutations are often caused by substances called mutagens. Base analogs, such as 5-bromouracil, a toxic drug used in cancer chemotherapy, are mutagens similar in structure to nucleotide bases. Other mutagens include coal tar dyes, which induce frame-shift mutations; ultraviolet light; atomic radiation; cigarette tars; some viruses, such as the genital herpes virus; and chronic irritants such as asbestos and silica. These mutagens are also referred to as carcinogens because they can lead to cancer, a condition in which cells fail to differentiate normally.