The picture below shows the process of transcription. During transcription, enzymes bind to a molecule of DNA. Then, the enzymes unwind and separate the DNA's double helical strands. As the molecule unwinds, complementary nucleotides pair with one of the DNA strands to form A. an identical strand of DNA. B. a protein molecule. C. a DNA polymerase. D. an RNA molecule.

Transcription is the first stage of protein synthesis involving the making of a complementary strand of mRNA from a DNA template. The process of transcription occurs in three major steps viz: INITIATION- where the enzyme called RNA polymerase binds to the promoter region of a gene and unwinds the DNA in order to read the nucleotide bases in the single strand. ELONGATION- After unwinding the DNA, the RNA polymerase adds nucleotides bases that are complementary to the original single DNA strand.

During elongation process, the Complementary base pairing rule is employed i.e. (A-U, G-C). If the RNA polymerase reads an Adenine base in the DNA, it synthesizes a Uracil base, if it reads Thymine, it synthesizes Adenine, the same goes for Guanine and Cytosine (vice versa).

N.B: The Thymine in the DNA is replaced by Uracil in the newly synthesized RNA molecule.

The last stage of transcription is when the RNA molecule attached to the single DNA strand is released.