$A$ nucleotide is composed of which subunits?

In mammals,histamine is secreted by .........

Excretion of nitrogenous waste products in semisolid form occurs in:

The compound,found in nature in gas phase but ionic in solid state is

If the lines,joining the origin to the points of intersection of the curve $2x^2 - 2xy + 3y^2 + 2x - y - 1 = 0$ and the line $x + 2y = k$,are at right angles,then $k^2$ equals

The logical statement $[ \sim ( \sim p \vee q) \vee (p \wedge r) ] \wedge ( \sim q \wedge r)$ is equivalent to