Isotonic Solutions are the best for animal cells
        
             
        
        
        
Because the common cold is cause by a ‘virus’.......
The answer is VIRUS 
        
             
        
        
        
Appalachian Mountains are a part of the Lithosphere
 
        
             
        
        
        
Answer:
7
Explanation:
water is neutral 7 is neutral ph
 
        
                    
             
        
        
        
In the apple maggot fly, the frequency of certain alleles increases steadily as one goes from North to South. This is an example of: Sympatric speciation.
Sympatric speciation is observed when there are no physical barriers which prevent any members of a species from mating with another, and all members are in close contact to one another. A new species, possibly established on a distinct food source or trait seems to develop instinctively.
The example of apple maggot fly supports a model for sympatric speciation in progress. Hawthorn is the native host for the apple maggot fly in North America. However, in the mid-1800s, a new population developed on introduced, domesticated apple. 
To learn more about Sympatric speciation here
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