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07/07/1861 American geneticist Nettie Maria Stevens is born

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Nettie Stevens Google Doodle. Nettie Stevens is the Discoverer of Sex Chromosomes

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Nettie Stevens discovery| Nettie Stevens experiment| Nettie Stevens facts & chromosomes

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Woman's History Month: Nettie Stevens

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Nettie Stevens Discovered XY Sex Chromosomes | She Didn't Get Credit | Nettie Stevens 155th Birthday

She discovered that sex is determined by the presence or absence of an X chromosome. Stevens studied beetles who produced two kinds of sperm, one with a large chromosome and one with a small chromosome. Eggs fertilized by the former developed in female offspring and sperm fertilized by the latter developed in male offspring.