Answer:
The correct answer is: geography and UV radiation.
Explanation:
Skin variation occurred thanks to evolution, and was driven as a consequence of the geographical location of different populations of humans. 
The humans that lived in hot and sunny places, closer to the equator, where much more exposed to the sun's ultraviolet radiation. In order to survive the amount of UV lights that they were exposed to, new humans in those regions were being born with a darker skin tone, which was rich in melanin (a brown pigment that protects us from the sun radiation).
Contrary to these humans that lived in the tropical areas, the humans that populated the areas that were closer to the poles, developed much lighter skin as a result of lower amounts of melanin in their skin. Since sun exposure in the poles is very limited, humans needed to receive as much as they could for the production of Vitamin D, and thus, their skins got lighter and less protected.
 
        
             
        
        
        
Answer:
The promoter region/sequence
Explanation:
Promoter sequences/region is where the transcription factors and RNA polymerase must attach before the gene can be transcribed. SO if we mutate this sequence, the transcription factors and RNA polymerase won't recognize it thus would not attach and transcribe the targeted gene.
 
        
             
        
        
        
Because there is a reflection from the sun hits the moon the moon reflects the light on earth
 
        
                    
             
        
        
        
A crevice is a narrow opening resulting from a split or a crack. <span />
        
             
        
        
        
Say for instance packaged ground beef meat or ground turkey meat. u could use a bio degradable packaging instead of styrofoam and plastic.