It is now possible to breed plants and animals with desired characters through:

Earthworms have no skeleton,but during burrowing the anterior end becomes turgid and acts as a hydraulic skeleton. It is due to

The thermally most stable compound is:

The angle between the lines whose direction cosines satisfy the equations $l+m+n=0$ and $l^2+m^2-n^2=0$ is

Which one of the following is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide?

$A$ $x : 1$ molar mixture of $He$ and $CH_4$ is contained in a vessel at $20 \ bar$ pressure. Due to a hole in the vessel,the gas mixture leaks out. If the composition of the mixture effusing out initially is $8 : 1$,then the value of $x$ will be