Which of the following is used as a screening agent in the replica plating experiment?

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 $(SNPs)$.

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

Column $X$	Column $Y$
$(1)$ Chromosome	$(P)$ Genetic code
$(2)$ $m-RNA$	$(Q)$ Gene
$(3)$ $t-RNA$	$(R)$ Ribosome
$(4)$ $r-RNA$	$(S)$ Anticodon

Match the enzyme in Column $I$ with its role in Column $II$:

Column $I$	Column $II$
$1$. Ligase	$a$. Peptide bond formation
$2$. Ribozyme	$b$. Hydrolysis of lactose
$3$. Permease	$c$. Joining of Okazaki fragments
$4$. $\beta$-galactosidase	$d$. Increases permeability

Choose the correct answer from the following options.

Match the researchers in Column-$I$ with their work given in Column-$II$.

Column-$I$	Column-$II$
$i$. Avery,McCarty,and MacLeod	$a$. $DNA$ digested by DNAse inhibits transformation of $R$ cells to $S$ cells.
$ii$. Griffith	$b$. $DNA$ replication is semi-conservative.
$iii$. Hershey and Chase	$c$. Used Streptococcus pneumoniae.
$iv$. Meselson and Stahl	$d$. Used radioactive Sulphur and Phosphorus.

Select the correct option from the following.

Explain the following terms:
$1.$ Leading strand - Lagging strand
$2.$ $t-RNA$ - $m-RNA$
$3.$ Monocistronic - Polycistronic