I think it’s erosion... not sure what you’re asking
Explanation:
Melanin is the pigment which absorbs UV light and it is present in skin and gives black colour to it.As we can see africans usually have black skin as they have to face direct uv light.
B. both diseases affect muscle control
<span>Factors that can increase mutation rates are high and low temperatures, food additives, and UV rays. All of these answers are correct. Mutation rates in genes vary depending on many environmental effects. UV rays, along with varying temperatures, can cause mutations during cell division due to the damage they impart on the cells that are dividing. Dangerous food additives are believed to cause mutations, as seen in animal studies (ie. aspartame causing cancer in rats).</span>