$DNA$ contains

Assertion: In a $DNA$ molecule,$A-T$ rich parts melt before $G-C$ rich parts.
Reason: In between $A$ and $T$ there are three $H-$ bonds,whereas in between $G$ and $C$ there are two $H-$ bonds.

Match the following columns:

Column-$I$	Column-$II$
$P$. Bacteriophage $\phi \times 174$	$I$. $5386$ nucleotides
$Q$. Bacteriophage lambda	$II$. $48502 \, bp$
$R$. Escherichia coli	$III$. $3.3 \times 10^9 \, bp$
$S$. Human haploid $DNA$	$IV$. $4.6 \times 10^6 \, bp$

The average length of $hnRNA$ in humans is

Genes are arranged on .......

Which of the following statements is true for $DNA$?