$PCR$ is used to:

In the given figure,what do '$R$','$S$',and '$T$' represent respectively?

Match the following:-

Column-$I$	Column-$II$
$(A)$ $\text{YAC}$	$(I)$ Separation of $\text{DNA}$ fragments
$(B)$ $\text{Hind II}$	$(II)$ Yeast
$(C)$ Gel electrophoresis	$(III)$ First restriction endonuclease
$(D)$ Heterologous host	$(IV)$ Recombinant protein

Find the correct match.

$I$	$II$	$III$
$(a)$ $PCR$	$(i)$ Specific base sequence	$p.$ $Taq$ polymerase
$(b)$ Downstream processing	$(ii)$ Inheritable gene	$q.$ Ampicillin resistant
$(c)$ Restriction endonuclease	$(iii)$ Amplification of $DNA$	$r.$ $E. coli$
	$(iv)$ Product separation and modification	$s.$ Quality control

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

List-$I$	List-$II$
$A$. Genetically modified organism	$I$. Agrobacterium tumefaciens
$B$. $DNA$ polymerase	$II$. Bt cotton
$C$. Ti plasmid	$III$. Thermus aquaticus
$D$. pBR322	$IV$. Escherichia coli

Choose the correct answer from the options given below:

Assertion $:-$ The tumor inducing $(Ti)$ plasmid of $Agrobacterium$ $tumefaciens$ has now been modified into a cloning vector.
Reason $:-$ Retroviruses have been disarmed and are now used to deliver genes into animal cells.