In bryophytes and pteridophytes,transport of male gametes requires:

An atomic power nuclear reactor can deliver $300 \ MW$. The energy released due to the fission of each nucleus of a uranium atom $^{238}U$ is $170 \ MeV$. The number of uranium atoms fissioned per hour will be:

Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest $pH$?

An electron collides with an atom in its ground state at rest. The atom then emits a photon of energy $E_{photon}$. In this process,the change $\Delta E_{elec}$ in the electron's energy is

$DDT$ residues are rapidly passed through food chains causing biomagnification. What is the reason for this?

Identify $A$ and $B$ in the following reactions: