Overview:Thirteen breakthroughs in the science of living things: Anton van Leeuwenhoek's discovery of micro-organisms, Robert Brown's identification of cell nuclei, Carl Woese's Archaea classification, Walther Flemming and Eduard Strasburger's discovery of mitosis, August Weismann's conclusions on meiosis, Awareness of cell differentiation and stem cells, Pinpointing of mitochondria, Hans Krebs' citric acid cycle, The discoveries of neurotransmitters, hormones and photosynthesis, Arthur George Tansley's ideas on ecosystems, and the centuries-long process of studying biodiversity.