Answer to Question 1
d
Answer to Question 2
Latitude, season, and time of day all have dramatic effects on vitamin D synthesis and status. Heavy cloud cover, smoke, or smog blocks the ultraviolet (UV) rays of the sun that promote vitamin D synthesis. Differences in skin pigmentation, latitude, and smog may account for the finding that African Americans, especially those in northern, smoggy cities, are most likely to be vitamin D deficient and develop rickets. Vitamin D deficiency is especially prevalent in the winter and in the Arctic and Antarctic regions of the world. To ensure an adequate vitamin D status, supplements may be needed. The body's vitamin D supplies from summer synthesis alone are insufficient to meet winter needs.
The tiger, Panthera tigris, was historically found throughout much of Asia, but at low population de
Natural selection of a population for dark coloration.
Feral Jackson's Chameleon from a population introduced to Hawaii in the 1970s
The adrenal glands. These glands sit on top of each kidney. Each adrenal is subdivided into an outer
The Parietal Reach Region
Marking for Population Study