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"Conception." 12 February 2005. HowStuffWorks.com. <http://health.howstuffworks.com/adam-200112.htm> 13 May 2008.
Conception
During sexual intercourse (sex), sperm is released into the cervix. They swim up the fallopian tubes. The egg cell moves down through the fallopian tube. The sperm meet the egg. One penetrates the egg, and the outer membrane of the egg locks out the other sperm cells. The sperm cell releases its nucleus, which combines with the egg's DNA to create a zygote.
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