Ask unlimited questions for free
Urine turns bright yellow if larger than normal amounts of certain substances are consumed; one of these substances is asparagus.
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
For a complete list of videos, visit our video library