The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Did you know?
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
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Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
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On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
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Approximately one in three babies in the United States is now delivered by cesarean section. The number of cesarean sections in the United States has risen 46% since 1996.
Fetal development of human
Types of tissue in the human body.
Explaining Behavior
The human chromosome set
Human Diseases Associated with Copy Number Variants
The proposed evolutionary development of the mammalian