|
|
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
The familiar sounds of your heart are made by the heart's valves as they open and close.
The first oncogene was discovered in 1970 and was termed SRC (pronounced "SARK").
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.
An identified risk factor for osteoporosis is the intake of excessive amounts of vitamin A. Dietary intake of approximately double the recommended daily amount of vitamin A, by women, has been shown to reduce bone mineral density and increase the chances for hip fractures compared with women who consumed the recommended daily amount (or less) of vitamin A.