$A$ : $5S$ $rRNA$ and surrounding protein complex provides binding site of $tRNA$.
$R$ : $tRNA$ is soluble $RNA$ with unusual bases.

The alternative valence states of $DNA$ bases in $A=T$ and $G=C$ pairs are known as:

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. Monocistronic gene	$I$. Coding sequence
$B$. Polycistronic gene	$II$. Intervening sequence
$C$. Exons	$III$. Mostly prokaryotes
$D$. Introns	$IV$. Mostly eukaryotes

How many of the given statements $(i-iv)$ is/are correct?
$i.$ In transcription,adenosine pairs with uracil.
$ii.$ Regulation of lac operon by repressor is referred to as positive regulation.
$iii.$ The human genome has approximately $50,000$ genes.
$iv.$ Haemophilia is a sex-linked recessive disease.

Select the correct match for $X$ and $Y$:

Column $X$	Column $Y$
$(1)$ $DNA$	$(P)$ Most abundant
$(2)$ $m-RNA$	$(Q)$ Various types based on anticodons
$(3)$ $t-RNA$	$(R)$ Carries information as genetic code
$(4)$ $r-RNA$	$(S)$ $A$ specific part acts as a template

Read the following statements carefully and choose the correct statements.
$(A)$ In a transcription unit,the promoter is located at the $5'$ end of the coding strand.
$(B)$ The single strand $DNA$ having the polarity $5' \rightarrow 3'$ is the template strand.
$(C)$ $RNA$ polymerase binds to the operator during transcription.
$(D)$ Single base $DNA$ differences occurring in humans are called Single Nucleotide Polymorphisms $(SNPs)$.