**The Discovery of Penicillin** **A)** Alexander Fleming, a professor of bacteriology at St. Mary's Hospital in London, is credited with the discovery of penicillin in 1928. Returning from a holiday, Fleming noticed that one of his Petri dishes containing Staphylococcus bacteria had been contaminated by a blue-green mould. He observed that the colonies of bacteria surrounding the mould had been destroyed, while others further away remained intact. He identified the mould as Penicillium notatum and concluded that it was releasing a substance that inhibited bacterial growth. **B)** Although Fleming identified the potential of the substance, he faced significant challenges in isolating and mass-producing it. The compound was notoriously unstable, making it difficult to extract in significant quantities for medical use. Consequently, his findings were initially met with limited interest from the scientific community. It was not until over a decade later, in the late 1930s, that Howard Florey and Ernst Chain at the University of Oxford revisited Fleming’s work. They successfully developed methods to purify the substance, allowing for clinical trials that would eventually save countless lives during World War II. **C)** The impact of this discovery on modern medicine cannot be overstated. By the 1940s, mass production of penicillin began, marking the start of the antibiotic era. This development fundamentally changed the treatment of infectious diseases, turning previously fatal infections into manageable conditions. In 1945, Fleming, Florey, and Chain were jointly awarded the Nobel Prize in Physiology or Medicine. Today, the legacy of this discovery continues to influence research in pharmaceutical sciences, though the rise of antibiotic resistance remains a significant challenge for modern medical practitioners. --- **Questions 1-6** In which paragraph (A-C) is the following information found? Letters may be used more than once. 1. The scientists who helped refine the mass production of the substance. 2. The initial observation of how the mould affected bacteria. 3. The year in which the original discovery was formally recognized with an award. 4. The name of the specific mould that was discovered. 5. The reason why the substance was not immediately developed for widespread medical use. 6. The long-term medical challenge that persists despite the discovery.