|
|
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
The most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.
Asthma cases in Americans are about 75% higher today than they were in 1980.
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
![Sunlight on Mars is dimmer than on Earth. This photo of a Martian sunset was imaged by Mars Pathfind](https://biology-forums.com/gallery/47/medium_12359_13_01_13_5_57_10.jpeg)
![Some vehicles will display a message if an evaporative control system leak is detected that could ...](https://biology-forums.com/gallery/30/medium_548020_01_06_17_5_22_00_30145645.png)