Identify the structure shown in the figure.

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?

$A$ complete set of chromosomes or cell genes inherited as a unit from a parent is known as

Match the following columns:

Column-$I$	Column-$II$	Column-$III$
$(1) \ 1952$	$(a)$ Watson and Crick	$(i)$ Double helix model of $DNA$
$(2) \ 1928$	$(b)$ Friedrich Miescher	$(ii)$ Proof that $DNA$ is genetic material
$(3) \ 1869$	$(c)$ Griffith	$(iii)$ Nuclein
$(4) \ 1953$	$(d)$ Hershey and Chase	$(iv)$ Transforming principle

The point mutations $A$ to $G$,$C$ to $T$,$C$ to $G$,and $T$ to $A$ in $DNA$ are:

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