|
|
In the ancient and medieval periods, dysentery killed about ? of all babies before they reach 12 months of age. The disease was transferred through contaminated drinking water, because there was no way to adequately dispose of sewage, which contaminated the water.
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.
More than 50% of American adults have oral herpes, which is commonly known as "cold sores" or "fever blisters." The herpes virus can be active on the skin surface without showing any signs or causing any symptoms.
Certain rare plants containing cyanide include apricot pits and a type of potato called cassava. Fortunately, only chronic or massive ingestion of any of these plants can lead to serious poisoning.
There are approximately 3 million unintended pregnancies in the United States each year.
![(a) Longevity decreases with increased horn-length breeding value of harvested rams. (b) Mean-weight](https://biology-forums.com/gallery/47/medium_33_31_08_11_2_12_19_1620680.jpeg)
![Feedback mechanisms of the thyroid gland: (1) stimulus; (2) release of TSH; (3) release of thyroid h](https://biology-forums.com/gallery/47/medium_46687_29_12_14_8_33_50_19766545.jpeg)