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.
Answer:
James Watson and Francis Crick were mainly the first to build a model of a DNA structure. (Your welcome).
Explanation:
Natural system is former when various components get grouped together for a particular function
Most animal cells differentiate at an early stage
Answer:
b
Explanation:
The correct answer would be 45.
Assuming that the 10 soils are each represented by A, B, C, D, E, F, G, H, I, J.
A can combine with 9 others as: AB AC AD AE A F AG AH AI AJ
B can combine as: BC BD BE BF BG BH BI BJ
C as: CD CE CF CG CH CI CJ
D as: DE DF DG DH DI DJ
E as: EF EG EH EI EJ
F as: FG FH FI FJ
G as: GH GI GJ
H as: HI HJ
I as: IJ
Adding all the combinations together = 45
In other words;
=
= 45