Transcription is

Which of the following statements are correct with reference to a transcription unit?
$A$. $A$ transcription unit in $DNA$ is defined primarily by three regions: promoter, structural gene and terminator.
$B$. The promoter is said to be located towards the $5'$-end of the structural gene.
$C$. The promoter is a $DNA$ sequence that provides binding site for $RNA$ polymerase.
$D$. The promoter defines the template and coding strands.
$E$. The terminator is located towards the $3'$-end of the coding strand and it defines the end of the process of transcription.
Choose the correct answer from the options given below:

Identify $X$ in the given figure.

Provide definitions and explanations for the following terms: Exons,Introns,Capping,and Tailing.

During transcription,if the nucleotide sequence of the $DNA$ strand that is being coded is $ATACG$,then the nucleotide sequence in the $mRNA$ would be:

The $TATA$ box of a eukaryotic promoter lies: