How much of the DNA is transcribed into each mRNA Molecule?

In eukaryotic cells, typically only a small portion of the DNA is transcribed into mRNA for each protein-coding gene, usually encompassing the gene's exons and some flanking intronic sequences. Each mRNA molecule represents a specific gene, consisting of about 1-2% of the total DNA in the genome. This transcription process is tightly regulated, allowing cells to produce only the necessary mRNAs for specific functions under varying conditions. Thus, while the entire genome contains the information, only select segments are actively transcribed into mRNA at any given time.