________ plays a role in determining skin color.
A. The HbS allele
B. Ultraviolet radiation
C. Sickle-cell anemia
D. Lactose intolerance
E. Lactose tolerance
Question 2
Some populations like the Polynesians, the San, or the people of southern India have phenotypes that do not fit neatly into standard racial categories, which suggests that
A. it is best to classify humans into a large number of racial categories.
B. phenotypical variation between human populations involves gradual shifts across different geographic zones.
C. these populations must have originated sometime before the major racial groups originated.
D. traditional concepts of race need to be reworked so that they are more exclusive.
E. there has been a lot of gene flow in the time since the origin of the three major human races.
The sea urchin Diadema on a coral reef. Feeding by Diadema appears to play a key role in the interac
Color-enhanced X-ray of the colon taken during a barium enema.
Psoriasis. This photograph demonstrates the characteristic white skin patches of this condition.
Intramuscular drug administration: (a) cross section of skin showing depth of needle insertion
The Role of Summation in Long-Term Potentiation
Vitamin C deficiency can cause skin hemorrhages