Before revision: The questions in the experimental and theoretical research in the field of interaction of weak influences of various fields with biological objects in conditions when an intense of the influence is smalland weak perturbation are analyzed.
After revision: The effect of ultralow-frequency or static magnetic and electric fields on biological processes is of huge interest for researchers due to the resonant change of the intensity of biochemical reactions although the energy in such fields is small. A simplified model to study the effect of the weak magnetic and electrical fields on fluctuation of the influence is smalland weak perturbation are analyzed.