They are all made to do a different and specialized job
        
                    
             
        
        
        
Answer:
Quite literally Everything
 
        
                    
             
        
        
        
Answer:
A-T 
Explanation:
purine adenine (A) always pairs with the pyrimidine thymine (T)
pyrimidine cytosine (C) always pairs with the purine guanine (G)
 
        
             
        
        
        
Answer:
Osteoclasts are the type of cells which are responsible for the absorption of calcium from bones. 
Explanation:
Osteoclasts is special type of cells which is released by parathyroid gland when the blood have low levels of calcium. Osteoclasts absorb calcium from the bones and add this calcium into the blood to increase the calcium level. If calcium is present in very high amount so this calcium is stored in the bones of the body and extracted when needed by the body. 
 
        
             
        
        
        
I believe the answer is comparative anatomy. It is the study of the similarities and differences in the structures of different species. Similar body parts may be homologies or analogies, such that both provide evidence of evolution. Similarities in embryos are evidence of common ancestry. For example all vertebrates embryos  have gill slits and tails.