As a NES, but not a teacher, I could suggest:
"I was in my eighth grade when I first learnt about Gregor Mendel's theories of heredity. It intrigued me how such small factors, then known, had the potential to determine the traits of an individual. Most importantly, Mendelís unwavering dedication and perseverance to prove what he believed in motivated me to display the same thirst to excel in my academics."
Hope this helps