Births on July 7

Nettie Stevens

Born on July 7, 1861

Nettie Stevens, American geneticist (d. 1912)

Nettie Maria Stevens (July 7, 1861 – May 4, 1912) was an American geneticist who discovered sex chromosomes. In 1905, soon after the rediscovery of Mendel's paper on genetics in 1900, she observed that male mealworms produced two kinds of sperm, one with a large chromosome and one with a small chromosome. When the sperm with the large chromosome fertilized eggs, they produced female offspring, and when the sperm with the small chromosome fertilized eggs, they produced male offspring. The pair of sex chromosomes that she studied later became known as the X and Y chromosomes.

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Nettie Stevens

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Events on 1861

19 Jan

Georgia (U.S. state)
American Civil War: Georgia joins South Carolina, Florida, Mississippi, and Alabama in declaring secession from the United States.
21 Jan

Jefferson Davis
American Civil War: Jefferson Davis resigns from the United States Senate.
20 Apr

Robert E. Lee
American Civil War: Robert E. Lee resigns his commission in the United States Army in order to command the forces of the state of Virginia.
8 May

Richmond, Virginia
American Civil War: Richmond, Virginia is named the capital of the Confederate States of America.
6 Sep

Ulysses S. Grant
American Civil War: Forces under Union General Ulysses S. Grant bloodlessly capture Paducah, Kentucky, giving the Union control of the Tennessee River's mouth.

Births on July 7

Nettie Stevens

Born on July 7, 1861

References

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Events on 1861

Georgia (U.S. state)

Jefferson Davis

Robert E. Lee

Richmond, Virginia

Ulysses S. Grant