We examine the in—uence of large-scale perturbations of gravitational potential on the spatial distribu- tion of galaxies and dark matter (DM). For appropriate parameters of the power spectrum, the cosmo- logical model, and the mass of dark matter particles, such perturbations can produce the wall-like superlarge-scale structure. Dynamics and parameters of the walls found in observations and simulations are related to the moments of the power spectrum. The wall-like elements are identi—ed with the Zeldo- vich pancakes (caustics) that form as a result of galaxy infall into the largest and deepest gravitational potential wells. Their properties are sensitive to the power spectrum and the background cosmological model, and they can be used to test and discriminate between diUerent models. When reheating of the baryonic component at redshifts and is allowed, the same perturbations produce sig- z \ z h 5 " z h " 10 ni—cant large-scale modulation of the spatial galaxy distribution relative to the more homogeneous DM distribution (large-scale bias). Subject headings: cosmology: theorygalaxies: clusters: generallarge-scale structure of universe