Where is the transcription unit found?

What do the processes $1$ and $2$ represent in the following sequence?
$TAC \, AAG \, GCG \, AUA \, CGA$
$\downarrow (1)$
$AUG \, UUC \, CGC \, UAU \, GCU$
$\downarrow (2)$
$Met - Phe - Arg - Tyr - Ala$

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

Messenger $RNA$ $(mRNA)$ is produced in:

In the process of transcription, the sigma factor is important for:

Which sequences do not code for $RNA$ or proteins?