What is the primary method of gene expression regulation in eukaryotes?

The primary method of gene expression regulation in eukaryotes is through controlling transcription of a gene. This process acts at the level where the DNA is transcribed into messenger RNA (mRNA). By regulating transcription, the cell decides whether or not to produce the corresponding mRNA based on various factors, including the developmental stage of the organism, the type of tissue, and environmental signals.

Transcriptional regulation involves a range of mechanisms, including the binding of transcription factors to specific DNA sequences near the gene, the modification of chromatin structure to either promote or inhibit access to the DNA, and the involvement of enhancers and silencers that can amplify or suppress transcription. This level of control is crucial, as it allows the cell to respond flexibly to internal and external changes, ensuring that the right genes are expressed at the right times and in the right amounts.

While the other options concern important aspects of gene expression regulation, they occur after transcription. Controlling translation, for instance, regulates how much of a protein is produced from the mRNA, and while this is certainly significant, it is not the primary method of regulation in eukaryotic cells. Similarly, degrading proteins and making mRNA more unstable are post-translational mechanisms, which