$DNA$ generally acts as a template for the synthesis of:

The one-gene-one-enzyme relationship was first established in.....

Identify the structure shown in the figure.

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.

Assertion : Histones are basic proteins of major importance in packaging of eukaryotic $DNA$. $DNA$ and histones comprise chromatin forming the bulk of eukaryotic chromosome.
Reason : Histones are of five major types $H_1, H_2A, H_2B, H_3$ and $H_4$.

Genetic mutations occur in which of the following?