How is mRNA produced in the nucleus of a cell?

Genes in DNA encode protein molecules. The first step of expressing a gene is transferring the information in DNA to a messenger RNA (mRNA) molecule, by a process called transcription. DNA Helicase unwinds the DNA double helix by breaking the hydrogen bonds down the centre of the strand. One strand of the DNA acts a template for complementary base-pairing. RNA nucleotides are attracted to the exposed bases and they are joined together by RNA polymerase. The resulting pre-mRNA molecule is then spliced to remove introns, and the resulting single stranded mRNA can then be used for translation into a protein molecule.