Relier Pairs 4.4 Cell TheoryVersion en ligne History and Basic concepts of cell theory par Jorge Arizpe 1 He was the first scientist to observe live microorganisms. 2 Postulate 3: All cells come from ________ 3 Postulate 2 The cell is the structural unit and the _______ 4 I conclude after studying plant tissues that all plants are made up of cells. 5 Postulate 1: All the organisms ..... 6 He said that all animal tissues are composed of cells 7 Scientist who observed cells in cork for the first time. He calls them celle. 8 He said that all cells are produced by dividing existing cells.