The variations of the normalised quasilinear particle and energy fluxes with artificial changes in the density and temperature gradients, as well as the variations of the linear growth rates and real frequencies, for ion temperature gradient and trapped-electron modes, are calculated. The quasilinear fluxes are normalised to the total energy flux, summed over all species. Here, realistic cases for tokamaks and spherical torii are considered which have two impurity species, specifically cases for the Joint European Torus (JET) and the National Sperical Torus Experiment (NSTX) . For situations where there are substantial changes in the normalised fluxes, the "diffusive approximation", in which the normalised fluxes are taken to be linear in the gradients, is seen to be inaccurate. In the case of artificial changes in density or temperature gradients, changes in the fluxes of different species ("off-diagonal") generally are significant, or even dominant, compared to those for the same species ("diagonal").