Ethos, in rhetoric, the character or emotions of a speaker or writer that are expressed in the attempt to persuade an audience. It is distinguished from pathos, which is the emotion the speaker or writer hopes to induce in the audience.
Examples of ethos can be shown in your speech or writing by sounding fair and demonstrating your expertise or pedigree: "As a doctor, I am qualified to tell you that this course of treatment will likely generate the best results."
Well if you think about it photosynthesis shows how the plants evolves so if you were to use a diagram that would support the fact that leaves take in nutrients and energy.
