Explanation: Transcription is a process by which an mRNA is synthesized using a DNA template. It is the process of copying the genetic message encoded in a DNA into an RNA. This process is catalyzed by an enzyme known as RNA polymerase. The RNA polymerase requires a DNA template, four oligonucleotides (ATP, UTP, CTP, and GTP) as precursors for RNA synthesis. The newly synthesized mRNA is complementary to the template strand of DNA in the sense that wherever adenine is found in the DNA template strand uracil occurs in the mRNA strand, wherever thymine occurs in the DNA template strand, adenine is found in the mRNA strand and wherever guanine occurs in the DNA template, cytosine occurs in the mRNA strand.
