5. Gregor Mendel:

Gregor Johann Mendel was an Austrian scientist and he became famous after he discovered how the genetics worked. Gregor was basically an uneducated monk before becoming a scientist. We can say that his discovery of modern genetics was accidental because he did not particularly focus on discovering it. It was when he was gardening; he came across some interesting things about his pea plant like its colors, the pea size etc. So, after couple of experiments he had accidentally discovered the modern genetics and these findings are at present considered as the basis for all we know about DNA and inheritance today. You must also need to know that his discovery remained unnoticed for decades until the 20^th century when his work was rediscovered.