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 thick bark of the cork oak of the Mediterranean region protects the tree from fire.
Flipper tags have been extensively used in the study of penguin population dynamics.
An inguinal hernia. A portion of the small intestine is protruding through the abdominal muscles int
Population Patterns: Tarim Basin
The population of Asia increases rapidly, the demand for food and water is also growing
Age-Standardized Suicide Rates (per 100 000 Population), Both Sexes, 2016