Search results
Results from the WOW.Com Content Network
Light skin pigmentation protects against depletion of vitamin D, which requires sunlight to make. [251] Human skin also has a capacity to darken (tan) in response to exposure to ultraviolet radiation. [252] [253] There is relatively little variation between human geographical populations, and most of the variation that occurs is at the ...
Anemia (also spelled anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen.This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin available for oxygen transport, or abnormalities in hemoglobin that impair its function.