B) they work independently of one other
        
                    
             
        
        
        
The nucleus of the cell directs cell activity and acts like the control center. This is the place where gene activity is controlled in terms of the replication of the genes. In addition the movement and actions of the cell are also dictated from the nucleus. 
        
                    
             
        
        
        
Answer:
The four main classes of organic compounds (carbohydrates, lipids, proteins, and nucleic acids) that are essential to the proper functioning of all living things are known as polymers or macromolecules. All of these compounds are built primarily of carbon, hydrogen, and oxygen but in different ratios.
Explanation:
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Answer: By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
Explanation:
 
        
             
        
        
        
A because it is used to treat known diseases.