Electromagnetic fields and therefore waves are generated orthogonal to the electric current that generated it.
The answer to this is DNA.
Positron Emission Tomography scan of the brain of cocaine addicts showed that the drug affects how the brain use glucose. Cocaine users' brain cannot use glucose efficiently and there are also reduced metabolic activity in other areas of the brain.
What the larva and pupa stages have in common is that both stages take place in water.
This is where the insect evolves until it becomes fully grown and then leaves water.
