Final answer:
True. The effect of a single gene regulatory protein can still be decisive in switching any particular gene on or off, even though control of eukaryotic gene expression is combinatorial.
Step-by-step explanation:
True. Control of eukaryotic gene expression is combinatorial, but the effect of a single gene regulatory protein can still be decisive in switching any particular gene on or off. In eukaryotes, gene expression can be regulated at various levels including epigenetic, transcriptional, post-transcriptional, translational, and post-translational. Transcriptional control is a common form of gene regulation in eukaryotes, where the binding of transcription factors to regulatory regions can either increase or prevent gene transcription. Examples of transcriptional control include the binding of transcription factors to enhancers or promoter sequences to augment or prevent transcription.