Instructions Full Game: These are multiple-choice quizzes with four possible answer choices that include all questions in a given set.     
Identify the following individual:

Lived: 1902 - 1992
They showed that genes switch the physical traits of an organism on or off, discovered chromosomal crossover, which increases genetic variation in species, and discovered transposition - that genes can move about within chromosomes.
Pierre-Simon Laplace
William Harvey
Lise Meitner
Barbara McClintock