Solution:
Genetically similar organisms respond in a similar way to certain carcinogenic stimuli because their response or predisposition or not a predisposition to certain stimuli depends on their genome or genetic material. Now, since the effect of a dye is being compared in the same organism, the control group and the experimental group must be similar organisms, otherwise, we would not be able to measure the damage caused by the dye in one of the organisms since there is no a reference from the same healthy organism.