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Name: JC
Status: Student
Grade:  9-12
Location: MA
Country: United States
Date: September 2005

When did science actually find out about the male determining the sex of the child?

The Y chromosome was discovered in fruit flies by Thomas Hunt Morgan circa 1910. Up until 1956, the number of chromosomes in humans was thought to be 48, but improved methods of observing chromosomes microscopically revealed that there were actually only 46 chromosomes in humans. I wasn't able to determine the exact year in which human females carry 2 X xhromosomes and males only one plus a Y chromosome.

Ron Baker, Ph.D.

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