Pellagra is caused by the deficiency of

Match the following columns:

Column-$I$	Column-$II$
$P$. Gluconeogenesis	$I$. Conversion of glucose to glycogen
$Q$. Glycogenesis	$II$. Conversion of glycogen to glucose
$R$. Glycogenolysis	$III$. Formation of glucose from non-carbohydrate sources

$A$: Variations exist among different species of living organisms.
$R$: The sequence,type,and number of amino acids in the structure of a protein are fixed.

What kind of liquid is water at normal temperature?

At what temperature is the density of water maximum (in $^\circ \text{C}$)?

From what you have learnt,can you tell whether enzymes are bigger or $DNA$ is bigger in molecular size? How did you know?