Questions

The EPA stands for Environment Protection Agency in U.S which studies pollution and other environmental health hazards.

In terms of concentration of impurity (a.k.a impurity doping concentration, often abbreviated to doping concentration), from the highest to the lowest among the three regions of a bipolar junction, emitter, collector, and base are the correct order. The above order is independent of the type of BJT, npn or pnp

Single selled organisms are also known as Unicellular organisms in which they have only one cell.

Examples are :: Fungi, Algae, Amaeba, Paramaecium,...

Hence, all the above given options are single selled organisms.

Mitochondria which is present in both plant and animal cells supplies energy to the cells and hence called as the powerhouse of the cell.