Answer:
Explanation: When the cell increases in size, the volume increases faster than the surface area, because volume is cubed where surface area is squared. When there is more volume and less surface area, diffusion takes longer and is less effective. ... this is actually why cells divide.
Explanation:
The answer is; the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer
In Africa, due to its equatorial latitude location, receives direct sunlight at more or less 90 degrees most of the year. These highly concentrated rays increase the UV radiation exposure that can cause damage to cell DNA. Selection pressure, therefore, favored individuals with high melanin concentrations that protect against UV. Therefore population evolved towards high melanin densities in the skin.
