mRNA will serve as reference book that contains information as the DNA and its sequence is complementary to the DNA template.
The transfer of information in a DNA strand to a new molecule of messenger RNA is known as transcription. Thus, the process of transcription is carried out by an enzyme called RNA polymerase and a number of accessory proteins called transcription factors. However, DNA is copied into mRNA because mRNA will serve as reference book that contains information as the DNA and its sequence is complementary to the DNA template.