Did you know?

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.

Did you know?

The immune system needs 9.5 hours of sleep in total darkness to recharge completely.

Did you know?

The first oncogene was discovered in 1970 and was termed SRC (pronounced "SARK").

Did you know?

People about to have surgery must tell their health care providers about all supplements they take.

Did you know?

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).

For a complete list of videos, visit our video library