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