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

(N/A) Three major types of $RNAs$ found in bacteria are:
$(i)$ $mRNA$ (messenger $RNA$): It provides the template for translation.
$(ii)$ $tRNA$ (transfer $RNA$): It brings amino acids and reads the genetic code.
$(iii)$ $rRNA$ (ribosomal $RNA$): It plays structural and catalytic roles during translation.
All three $RNAs$ are needed for the synthesis of a protein in a cell.
There is a single $DNA$-dependent $RNA$ polymerase that catalyzes the transcription of all types of $RNA$ in bacteria.
The process of transcription in bacteria involves three stages:
$1$. Initiation: $RNA$ polymerase binds to the promoter region on $DNA$ and initiates transcription. It associates transiently with the initiation factor $(\sigma)$ to start the process.
$2$. Elongation: The $RNA$ polymerase uses nucleoside triphosphates as substrates and polymerizes them in a template-dependent fashion, following the rule of complementarity. It facilitates the opening of the $DNA$ helix and continues elongation.
$3$. Termination: Once the polymerase reaches the terminator region, the nascent $RNA$ falls off, as does the $RNA$ polymerase. It associates with the termination factor $(\rho)$ to terminate the transcription. Association with these factors ($\sigma$ and $\rho$) alters the specificity of the $RNA$ polymerase to either initiate or terminate the process.