|
|
Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.
Always store hazardous household chemicals in their original containers out of reach of children. These include bleach, paint, strippers and products containing turpentine, garden chemicals, oven cleaners, fondue fuels, nail polish, and nail polish remover.
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."
![In 2008, the U.S. economy suffered a gaping wound as several trillion dollars were ripped out of it.](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_33_47_22176335.png)
![Shortly after his death, George Washington had already become myth—part Moses, part angel—in this wo](https://biology-forums.com/gallery/47/medium_374628_16_08_15_9_52_07_22255346.jpeg)
![When Union troops pushed toward Richmond in June of 1862, these slaves crossed the Rappahannock Rive](https://biology-forums.com/gallery/47/medium_376021_22_08_15_1_40_22_22353567.jpeg)
![In 2010 protesters in Washington, D.C., demanded that the Obama administration support liberalized i](https://biology-forums.com/gallery/47/medium_27_24_08_15_1_42_55_22410556.jpeg)