We use a combination of theoretical predictions and A-phage DNA single molecule fluorescence microscopy to study the behavior of polymers tethered to surfaces. Brownian dynamics simulations of a number of coarse-grained polymer models-dynamic and equilibrium Kratky-Porod chains as well as bead-spring chains-were completed and compared with analytical and experimental results. Experiments of tethered lambda-phage DNA in shear flow are presented for the first time in the flow-gradient plane. Cyclic dynamics-where the polymer continuously diffuses away from the wall, subsequently undergoes stretch in the flow direction, is then "entropically pulled back" toward the wall, and finally recoils-were observed and quantified through correlations and power spectral densities.