« previous next »
« previous next »
 

Did you know?

Before a vaccine is licensed in the USA, the Food and Drug Administration (FDA) reviews it for safety and effectiveness. The CDC then reviews all studies again, as well as the American Academy of Pediatrics and the American Academy of Family Physicians. Every lot of vaccine is tested before administration to the public, and the FDA regularly inspects vaccine manufacturers' facilities.

Did you know?

Hippocrates noted that blood separates into four differently colored liquids when removed from the body and examined: a pure red liquid mixed with white liquid material with a yellow-colored froth at the top and a black substance that settles underneath; he named these the four humors (for blood, phlegm, yellow bile, and black bile).

Did you know?

There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.

Did you know?

All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.

Did you know?

The shortest mature adult human of whom there is independent evidence was Gul Mohammed in India. In 1990, he was measured in New Delhi and stood 22.5 inches tall.

Transcription Factor Transcription Factor
Alternative pathway recognition and activation. C3w is on the surface of the microbe; factor B binds ... Alternative pathway recognition and activation. C3w is on the surface of the microbe; factor B binds ...
Organic approaches and the reduction of inputs and pollution Organic approaches and the reduction of inputs and pollution
Dilution Factor Dilution Factor
How the multiple-factor hypothesis accounts for the 1:4:6:4:1 phenotypic ratio How the multiple-factor hypothesis accounts for the 1:4:6:4:1 phenotypic ratio
Summary of the inputs and outputs of photosynthesis. Summary of the inputs and outputs of photosynthesis.
Video: Homeostasis (range of body conditions, normal limits, mild stresses & severe stresses)

For a complete list of videos, visit our video library