Match the following and select the correct option:
Column $A$ | Column $B$
$(i)$ Oncogenes | $(1)$ Causes $AIDS$
(ii) Single circular $DNA$ | $(2)$ $Lac$-Operon concept
(iii) Splicing | $(3)$ Component of bacterial chromosome
(iv) Jacob and Monod | $(4)$ Processing of $mRNA$ molecules
| $(5)$ When activated cause cancer
Select the correct sequence for $(i), (ii), (iii), (iv)$ respectively.

The clover leaf model of $tRNA$ consists of:

Read the following statements $:-$
$(i)$ Eukaryotic $\text{mRNA}$ is polycistronic whereas prokaryotic $\text{mRNA}$ is monocistronic.
$(ii)$ Prokaryotic $\text{mRNA}$ is cap-less and tail-less whereas eukaryotic $\text{mRNA}$ is with cap and tail.
$(iii)$ The precursor of prokaryotic $\text{mRNA}$ is $\text{hnRNA}$.
$(iv)$ In replication,only one of the strands acts as a template.
$(v)$ In eukaryotes,transcription occurs in the nucleus and translation in the cytoplasm.
Which of the above statements are correct?

Genetic mapping of bacteriophage $\phi X174$ has been done by

Match List $I$ with List $II$.

List $I$	List $II$
$A$. Frederick Griffith	$I$. Genetic code
$B$. Francois Jacob and Jacques Monod	$II$. Semi-conservative mode of $DNA$ replication
$C$. Har Gobind Khorana	$III$. Transformation
$D$. Meselson and Stahl	$IV$. $Lac$ operon

Choose the correct answer from the options given below:

Define/Explain the following:
$1.$ Nucleotide
$2.$ Central Dogma