|
|
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.
Nearly 31 million adults in America have a total cholesterol level that is more than 240 mg per dL.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).
IgA antibodies protect body surfaces exposed to outside foreign substances. IgG antibodies are found in all body fluids. IgM antibodies are the first type of antibody made in response to an infection. IgE antibody levels are often high in people with allergies. IgD antibodies are found in tissues lining the abdomen and chest.