Are You Familiar with Elementary School History? Take This Quiz and Recall What You Remember From 3rd to 5th Grade.
While Alexander Fleming was a biologist and pharmacologist by profession, his most momentous discovery was unintentional and had a profound impact on medicine. What substance did he identify and isolate?

Correct Incorrect Penicillin - Alexander Fleming stumbled upon penicillin when he left a culture plate unattended in his laboratory before going on vacation. Upon his return, he discovered mold growth, a discovery that eventually led to the creation of the world's first true antibiotic.