Genomic deoxyribonucleic acid (abbreviated as gDNA[1]) is chromosomal DNA, in contrast to extra-chromosomal DNAs like plasmids.
[2] gDNA predominantly resides in the cell nucleus packed into dense chromosome structures.
When a cell is not dividing, chromosomes exist as loosely packed chromatin mesh.
Precursor mRNA (pre-mRNA) is transcribed by RNA polymerase II in the nucleus.
pre-mRNA is then processed by splicing to remove introns, leaving the exons in the mature messenger RNA (mRNA).