Which of the following does not contain $DNA$?

An enzyme that can stimulate germination of barley seeds is

$A$ torch bulb rated as $4.5\, W, 1.5\, V$ is connected as shown in the figure. The $e.m.f.$ of the cell needed to make the bulb glow at full intensity is ............. $V$.

The masses and radii of the earth and the moon are $M_1, R_1$ and $M_2, R_2$ respectively. Their centres are at a distance $d$ apart. The minimum speed with which a particle of mass $m$ should be projected from a point midway between the two centres so as to escape to infinity is:

Which was the first commercially developed insecticide?

The logic circuit shown below has the input waveforms $A$ and $B$ as shown. Pick out the correct output waveform.