Transcription: RNA made according to base sequence in DNA
30 base pairs (10 triplets) shown for example - actual genes are usually hundreds or thousands of base pairs in length
The two strands of DNA separate (under the influence of the enzyme RNA polymerase). When separate, the two strands are shown here in black and grey. Messenger RNA - here red - forms on one - black - strand of DNA. The other strand - grey - does not take part in the process.
The strand of messenger RNA (mRNA) formed then leaves the nucleus and passes into the cytoplasm. The opened-up section of DNA re-forms into a double helix, as before.