Where can a dichotomous key be found??

You can't find one. Look it up for examples and for info on it. It's a scientific tool.

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.