Abstract : Noise and fluctuations play an important role in the dynamics of driven non-equilibrium systems at microscopic length scale. In my talk I will briefly explain about the function of noise and fluctuations in some of the studied driven linear and nonlinear model systems, then I will talk about the biological processes particularly on transcription. Transcription is the preliminary process of genetic regulation and it is frequently interrupted with pauses/errors. These pauses/errors are of various types. The correction of errors or recovery of transcription involves the diffusive backward translocation (for the case of backtracking pauses) of RNA polymerase (RNAP) on the DNA template. A trailing RNAP on the same template can interfere with backtracking as it progressively restricts the space that is available for backward translocation and thereby ratchets the backtracked RNAP forward. I will mainly focus on the efficient mechanism of error correction method and how the efficiency of the error correction is affected by the RNA polymerase traffic. Finally with the help of a number of variants of a canonical exclusion model, I would explain different features of steady state particle flux in normal transport processes with a dynamical defect/blockage. This model can be applied in explaining the behavior of transcription flux in the presence of other kinds of pauses, such as DNA binding proteins.