Light skin is most adaptive in northern latitudes because
A) dark skin allows folate destruction when UV radiation is less.
B) the greater UV radiation in northern latitudes destroys vitamin D.
C) increased melanin causes an increase in the risk of melanoma.
D) light skin in northern latitudes allows adequate folate for fetal development.
Answer: D
You might also like to view...
Communities with a high level of bacterial diversity are found in many habitats including soil and aquatic environments. Recent studies indicate this diversity is crucial to the functioning of these communities. The same studies have also found that phage abundance plays a critical role in the maintenance of the bacterial diversity within these communities. Are phages a density-dependent or a density-independent regulating factor?
A. density-independent B. density-dependent
Spicules are secreted by
a. amoeboid cells. b. choanocytes. c. sperm. d. porocytes. e. pinacoderm.
Perpetually young tissues where cells retain the
ability to divide are a. vascular. b. meristematic. c. protective. d. photosynthetic. e. all of these.
The only survivors of a colony on Venus are a man and a woman, who both happen to originally be from southern
Ukraine. Their descendants will show the effect of ____.
a. genetic drift b. punctuated equilibrium c. excessive mutation d. heterozygote advantage e. frequency-dependent selection