Optical activity is shown by

$A, B$ and $C$ are three biomolecules. The results of the tests performed on them are given below:

	$\text{Molisch's Test}$	$\text{Barfoed Test}$	$\text{Biuret Test}$
$A$	$\text{Positive}$	$\text{Negative}$	$\text{Negative}$
$B$	$\text{Positive}$	$\text{Positive}$	$\text{Negative}$
$C$	$\text{Negative}$	$\text{Negative}$	$\text{Positive}$

$A, B$ and $C$ are respectively:

Which of the following is the most important biological molecule containing $Mg$ found in living organisms?

The artificial sweetener $X$ contains a glycosidic linkage and $Y$ contains amide and ester linkages. $X$ and $Y$ respectively are:

Which of the following statements are correct?
a) In maltose,$C-1$ of one $\alpha-D$-glucose is linked to $C-4$ of second $\alpha-D$-glucose.
b) Quaternary structure of protein represents spatial arrangement of two or more polypeptide chains with respect to each other.
c) Nucleotide units in a nucleic acid are joined to each other through a phosphodiester linkage.
d) Abnormally low level of thyroxine leads to hypothyroidism.

Match List-$I$ and List-$II$

List-$I$	List-$II$
$A$. Molisch's Test	$I$. Peptide
$B$. Biuret Test	$II$. Carbohydrate
$C$. Carbylamine Test	$III$. Primary amine
$D$. Schiff's Test	$IV$. Aldehyde

Choose the correct answer from the options given below: