Can you explain the process of DNA transcription?

The first stage of gene expression is DNA transcription. Transcription is the formation of single stranded mRNA from double stranded DNA. During transcription, the enzyme DNA helicase unwinds the double helix by breaking the hydrogen bonds between the complementary DNA base pairs. Free RNA nucleotides are attracted to exposed complementary DNA bases. These RNA nucleotides are bonded by RNA polymerase to form mRNA. This mRNA leaves the nucleus, through nuclear pores, where it is attracted to the ribosome in the cytoplasm.