|
|
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
In 1886, William Bates reported on the discovery of a substance produced by the adrenal gland that turned out to be epinephrine (adrenaline). In 1904, this drug was first artificially synthesized by Friedrich Stolz.
It is difficult to obtain enough calcium without consuming milk or other dairy foods.
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.
About 600,000 particles of skin are shed every hour by each human. If you live to age 70 years, you have shed 105 pounds of dead skin.
![Changes in boreal forest composition along a chronosequence in Quebec. Dates refer to the year of th](https://biology-forums.com/gallery/47/medium_33_17_02_12_6_53_46_20121657.jpeg)
![The phosphorus cycle. Numbers are 1012 g P or fluxes as 1012 g P per year (data from Schlesinger 199](https://biology-forums.com/gallery/47/medium_33_17_02_12_7_02_17_2037874.jpeg)