McClintock, Barbara

She was born in 1902 and died in 1992 and was one of the most influential individuals in the field of plant cytogenetics. She worked with maize her entire career and was the person who first described transposons and showed that gave the corn the modeled appearance. She was the 1983 Nobel Laureate in Physiology or Medicine for her transposon discovery. She also first described the technique od visualizing maize chromosomes under the microscope with speciific staining techniques and was able to show various different genetic occurences in corn such as translocations, inversions, transposons, genetic recombination and crossing-over.
She is the only woman to ever recieve an unshared nobel prize.
More information here