most of the answers are on here https://quizlet.com/78911237/bio-test-on-the-cell-membrane-osmosis-and-diffusion-8b-flash-cards/ just scroll down!!
Shleiden and Theodor Schwann were the first to recognize that all plants and animals are composed of cells.
Hope this helped :)
Because they are the essential micronutrients for the different metabolites of living organisms?