The written text can be defined as a medium of something that's written or transcripted from otherr texts. <u>The unique characteristic of a written text is that it lasts long than other mediums such as verbal, audio, etc</u>.
Example of this unique characteristic of longevity of written text are the historical books that were written ages ago and still exist such as Holy Scriptures, historical books for instance 'Of Plymouth Plantation', autobiographies, etc. If we compare the longevity of other mediums with written text, written texts lasts longer than the others.
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.