It selectively controls what goes in and out of the cell
A fuel cell works like a battery. It consists of two electrodes where the reactions would occur and an electrolyte solution which allows for caharged particles to flow. In a fuel cell that uses hydrogen and oxygen as reactants. The hydrogen would enter the cell at the anode where oxidation would happen. So that the species that is formed in the anode side would be hydronium ions and electrons. The oxygen, on the other hand, would enter the cathode electrode where reduction occurs. The species that are produced in this side of the cell are water molecules. Together, the net reaction is called a redox reaction.
A line of indirect evidence of competition comes from the comparison between closely related species, whose population can be allopatric (geographically separated) or sympatric (geographically superimposed). In some cases, the allopatric populations of these species are morphologically similar and use similar resources. On the other hand, sympatric population, which are supposed to compete for resources, have body structures and use different resources. The displacement of characters is the tendency to have more divergent characteristics in sympatric populations of two species than in allopatric populations of the same two species.
An example of character displacement is the variation in size between populations of galapagos finches. Some of its populations are allopatric ( they live separately) and others are sympatric ( they live together). Peak size distributions they vary according to whether they are sympatric or allopatric. They look more alike when they are allopathic than when they are sympatric. That is, the peak size character moves when species enter competition.
