Edexcel IGCSE Changes in Medicine c1845-c1945 Practice Test 2025 – All-in-One Mastery Guide to Ace Your Exam!

The important discovery made by Alexander Fleming in 1928 was the discovery of penicillin. This breakthrough occurred when Fleming noticed that a mold, Penicillium notatum, had contaminated one of his petri dishes containing Staphylococcus bacteria and was inhibiting bacterial growth around it. This observation led to the realization that the mold was producing a substance that could kill bacteria, which was subsequently named penicillin.

Fleming's discovery was groundbreaking as it marked the beginning of modern antibiotics, revolutionizing the treatment of bacterial infections and saving countless lives. The significance of penicillin was fully recognized and harnessed in the 1940s, but the initial discovery in 1928 laid the foundational work for the development of antibiotic therapies.

Other options, such as the discovery of vaccines, the development of anesthetics, and the introduction of X-rays, represent separate advancements in medical science but are not directly related to Fleming's groundbreaking work with penicillin. Each of those areas belongs to different contexts in the history of medicine and does not capture the essence of Fleming's contribution.