Final answer:
The correct option in the final answer are both a and b. ATP-dependent chromatin remodeling affects transcription by altering chromatin structure, which can lead to either the activation or suppression of gene expression. It involves modifications like histone acetylation or methylation, changing chromatin conformation without inducing mutations.
Step-by-step explanation:
ATP-dependent chromatin remodeling plays a crucial role in the regulation of gene expression. This process involves shifting the structure of chromatin, the complex of DNA and histone proteins, to either expose or conceal regions of the genome to transcription machinery. When chromatin remodeling results in the exposure of DNA, transcription factors and RNA polymerase can bind to the promoter regions of genes, leading to the activation of transcription. Conversely, when remodeling results in chromatin condensation, it can suppress gene transcription by making the DNA inaccessible.
Examples of chromatin remodeling include the acetylation or methylation of histones, which can either unwind or tighten nucleosomes, respectively. These reversible modifications do not mutate the DNA sequence itself, but rather influence the recruitment of proteins that alter chromatin conformation to regulate transcription. Since the essence of this remodeling is altering gene accessibility, it does not induce mutations, hence the correct options that describe its effects on transcription are both (a) Activation and (b) Suppression.