Which of the following vitamins are fat-soluble?

Find out a qualitative test for proteins,fats and oils,amino acids and test any fruit juice,saliva,sweat and urine for them.

The primary precursor for the production of cholesterol in our body is

Match List-$I$ with List-$II$:

$A$. Trypsin	$I$. Intercellular ground substance
$B$. Morphine	$II$. Lectin
$C$. Concanavalin	$III$. Enzyme
$D$. Collagen	$IV$. Alkaloid

Choose the correct answer from the options given below:

Why does carbon form a wide variety of compounds by combining with itself and other functional groups?

Assertion $A$: Living organisms obtain various molecules and elements from their environment.
Reason $R$: Living organisms synthesize components essential for their body.
Which option is correct for Assertion $A$ and Reason $R$?