in the 1920s, hermann muller discovered that x-rays caused genetic changes in the fruit fly drosophila. in a related series of experiments in the 1940s, other scientists discovered that other types of chemicals have a similar effect. a new chemical food additive is developed by a cereal manufacturer. why is it necessary to test for its ability to cause mutation? question 9 options: we want to be sure that it increases the rate of mutation sufficiently. we want to prevent any chance that it might cause mutations. we want to make sure that it does not emit radiation. we worry that it might cause mutation in cereal grain plants.