Consider statements about scientists: 1. Edward Jenner developed the smallpox vaccine. 2. Alexander Fleming discovered penicillin. 3. Louis Pasteur discovered the structure of DNA. Which are correct? MCQ with Answer and Explanation

Edward Jenner, an English physician, is credited with developing the world's first successful vaccine against smallpox in 1796, using material from cowpox lesions. Alexander Fleming, a Scottish bacteriologist, discovered the first true antibiotic, penicillin, in 1928, from the fungus Penicillium notatum. Louis Pasteur made immense contributions to microbiology and immunology, but the double helix structure of DNA was discovered by James Watson and Francis Crick in 1953. Thus, statements 1 and 2 are correct.