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Only 12 hours after an egg cell is fertilized by a sperm cell, the egg cell starts to divide. As it continues to divide, it moves along the fallopian tube toward the uterus at about 1 inch per day.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
The largest baby ever born weighed more than 23 pounds but died just 11 hours after his birth in 1879. The largest surviving baby was born in October 2009 in Sumatra, Indonesia, and weighed an astounding 19.2 pounds at birth.
There are approximately 3 million unintended pregnancies in the United States each year.
Human neurons are so small that they require a microscope in order to be seen. However, some neurons can be up to 3 feet long, such as those that extend from the spinal cord to the toes.