Removal of introns and joining of exons in a defined order during transcription is called

Which of the following statements are correct?
$i. r-RNA$ provides the template for synthesis of proteins.
$ii. t-RNA$ brings amino acids and reads the genetic code.
$iii. RNA$ polymerase binds to promoter and initiates transcription.
$iv. A$ segment of $DNA$ coding for a polypeptide is called an intron.

Explain different types of $RNA$ and explain the process of transcription.

If both strands of $DNA$ were to act as templates during transcription,then:

$A$ geneticist isolates a gene for a specific trait under study; she also isolates the corresponding $mRNA$. Upon comparison,the $mRNA$ is found to contain $1,000$ fewer bases than the $DNA$ sequence. Did the geneticist isolate the wrong $DNA$?

In prokaryotes, the transcription of $DNA$ is initiated with the help of