When was the scientist that  revealed by means of microscopy the previously unknown world of microorganisms born?
History of biology The history of biology traces the study of the living world from ancient to modern times. Although the concept of "biology" as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to ayurveda, ancient Egyptian medicine and the works of Aristotle and Galen in the ancient Greco-Roman world. This ancient work was further developed in the Middle Ages by Muslim physicians and scholars such as Avicenna. During the European Renaissance and early modern period, biological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Vesalius and Harvey, who used experimentation and careful observation in physiology, and naturalists such as Linnaeus and Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms. Antonie van Leeuwenhoek revealed by means of microscopy the previously unknown world of microorganisms, laying the groundwork for cell theory. The growing importance of natural theology, partly a response to the rise of mechanical philosophy, encouraged the growth of natural history (although it entrenched the argument from design).
Sydney Brenner Sydney Brenner (born 13 January 1927) is a South African biologist and a 2002 Nobel prize in Physiology or Medicine laureate, shared with Bob Horvitz and John Sulston. Brenner made significant contributions to work on the genetic code, and other areas of molecular biology while working in the Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge, England. He established the roundworm "Caenorhabditis elegans" as a model organism for the investigation of developmental biology, and founded the Molecular Sciences Institute in Berkeley, California, U.S..