The integumentary system (skin) has been called a membrane and an organ but, it is generally considered a system because it has organs that work together as a system. It is sometimes considered an organ because it contains several types of tissues and a membrane and it covers the body.
 
        
                    
             
        
        
        
Elliptical paths is wrong im trying circular paths b/c elliptical paths are circular
 
        
                    
             
        
        
        
Answer: The atom of carbon is able to form macromolecules because it has only four electrons in its outer shell. This is the reason why it can bond with four other carbon atoms. The bonds that it forms with other carbon molecules are very stable.
Explanation: I did my research and i also took Science class. :)
Hope this Helps :).
 
        
             
        
        
        
Do you need specific sources on this for a paper? I️ would use easybib it is a great source to get bibliographies done quick.