Explain (in one or two lines) the function of the followings:
$(a)$ Promoter
$(b)$ $tRNA$
$(c)$ Exons
$(a)$ Promoter
Promoter is a region of $DNA$ that helps in initiating the process of transcription. It serves as the binding site for $RNA$ polymerase.
$(b)$ $t R N A$
$tRNA $ or transfer $RNA$ is a small $RNA$ that reads the genetic code present on $mRNA$. It carries specific amino acid to $mRNA$ on ribosome during translation of proteins.
$(c)$ Exons
Exons are coding sequences of $DNA$ in eukaryotes that transcribe for proteins.
Definitions/Explanation : Cistron & terminator
How many types of ribonucleic acids are known
One strand of the given segment of $DNA$ codes for $mRNA$ having the sequence $AUC, GCG, UCA$ needed for synthesis of proteins. The strand by which $DNA$ molecule will be responsible for the above $mRNA$ sequence is
Full Forms : $SnRNA$
$A$ : Sigma factor of $RNA$ polymesase recognizes the start signal region in prokaryotes.
$R$ : Promotor region lies at $5^{\prime}$ of template strand, $?$