What is the process by which genetic information is transferred from $DNA$ to $RNA$?

What is the sequence of mRNA if the sequence of the coding strand in a transcription unit is written as $5'-ATGCATGCA-3'$?

What does $X$ represent in the following diagram?

Which of the following statements are correct with reference to the prokaryotic genome?
$A$. Monocistronic structural genes
$B$. Introns absent in structural genes
$C$. Transcription and translation are coupled processes
$D$. Primary transcript undergoes splicing
$E$. Only one $RNA$ polymerase is present

Which of the following enzymes can form $RNA$ from $DNA$?

Give an account of post-transcriptional modifications of a eukaryotic $mRNA$.