Question: When was the scientist that  revealed by means of microscopy the previously unknown world of microorganisms born?
Sentence (from "History of biology"): 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.
Relevant evidence: No