1. What are the two primary types of melanin and how do they differ?
2. Explain how the amount of eumelanin and number of melanosomes differ between a person with lighter color skin and a person with darker color skin.
3. Name two molecules in the body that UV radiation can damage.
4. What are the positive and negative effects of UVB exposure?
5. Your friend, who tans easily, argues that it’s great to get a tan because darker skin pigmentation offers lots more protection from damaging UV radiation, so he’s keeping himself safe. Would you agree? Explain.
6. Describe the relationship between the UV Index (the colored bar in Figure 1) and latitude (y-axis).
7. How do you explain the relationship between the UV Index and latitude? (In other words, why does UV intensity change with latitude?)
8. In the film, Dr. Jablonski explains that melanin, located in the top layer of human skin, absorbs UV radiation, protecting cells from the damaging effects of UV. Genetics determines the type of melanin (i.e.brown/black eumelanin or red/brown pheomelanin) and the amount of melanin present in an individual’s cells.

Based on this information, write a hypothesis for where in the world you would expect to find human populations with darker or lighter skin pigmentation (i.e., different amounts of melanin).