What does $snRNAs$ stand for?

During transcription,the holoenzyme $RNA$ polymerase binds to the $DNA$ strand,and the $DNA$ forms a saddle-like structure at that site. What is this sequence called?

$RNA$ polymerase-$I$ transcribes eukaryotic ribosomal $RNA$ which does not consist of: (in $S$ $rRNA$)

Write an explanatory note on the transcription unit and the gene.

Where is the $TATA$ box found?

$A$: Sigma factor of $RNA$ polymerase recognizes the start signal region in prokaryotes.
$R$: Promoter region lies at $5'$ end of the coding strand, not the template strand.