Formation of mRNA from DNA is called as transcription. It is heterocatalytic function of DNA. Template of DNA called sense strand (Master Strand) is involved. The segment of DNA involved in transcriptions is cistron, which has a promoter region where initiation starts and terminator region where transcription ends. Transcription is catalyzed by DNA dependent RNA polymerase. As RNA have uracil at the place of thymine. For given RNA the transcription unit will be