Which process copies instructions from DNA onto mRNA?

The process in which mRNA is made from DNA is called transcription. Transcription is the first part of the process of Protein Synthesis. Protein Synthesis consists of Transcription and Translation.
In Transcription double stranded DNA is used as a template to create a complementary single stranded mRNA. mRNA is created so it may leave the nucleus, as DNA cannot.
Once mRNA has left the nucleus it attaches to a ribosome starting the process of Transcription. In Transcription this mRNA is taken, and read to create a chain of amino acids and ultimately create a specific protein.

The process through which instructions are copied from the DNA to the mRNA is referred to as transcription. Transcription is the first part of the two-step process of protein synthesis that takes places in the nucleus of a cell. The second step is known as translation. During transcription, genetic instructions are copied from a DNA strand to produce a complementary mRNA strand. This strand is then transported to the ribosome where translation takes place, and a protein is made.
The process of transcription is further broken down into three steps, initiation, elongation, and termination. Initiation is the first step in which the enzyme RNA polymerase binds itself to a part of a gene and signals the DNA strand to unwind in readiness for the transfer of genetic codes. Elongation is when the RNA attaches to the DNA strand after it unwinds and the genetic information is replicated to form the mRNA molecule. The final step in this process is termination, which occurs when the mRNA strand detaches itself from the DNA.