Ask unlimited questions for free
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.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Approximately 15–25% of recognized pregnancies end in miscarriage. However, many miscarriages often occur before a woman even knows she is pregnant.
In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
For a complete list of videos, visit our video library