Answer:
i think it would be A (aka the first answer)
Explanation:
im sorry if im wrong
 
        
                    
             
        
        
        
Natural selection act directly upon <u>Alleles</u>
Explanation:
Genes, such as that of fur color, have many variants called alleles. Natural selection act on the alleles and chooses the best fit for an environment and eliminates the disadvantageous ones from the population over generations. Mutations are a rare occurrence that increases the number of allelic variants of a genes on which natural selection can act upon. 
 
        
             
        
        
        
Answer:
Yes, mixtures can be separated using a variety of techniques.
 
        
                    
             
        
        
        
Answer:
I think the answer is A
Explanation:
D is pointing at specifically at electron which is the outer charger of the electron cloud. I don't think its likely to be D as the answer.
 
        
             
        
        
        
DNA is a negatively-charged molecule. Also cell membranes are negatively charged. The problem would be how to push this charges together? I<span>f you put some CaCl2 into the mixture, the CaCl2 will "split" giving 2Cl- and Ca2+. This last ion will be attracted by the negatively charged DNA and will "cover" it, hiding its negative charge. Hope this answers the question.</span>