Answer:
nitrogen base
Explanation:
as it is nitrogen that is fixed to make protein bonds
 
        
                    
             
        
        
        
Answer:
Individuals with two X chromosomes and one Y chromosome are abnormally tall females of average  intelligence.
Explanation:
Individuals with this disorder are males.
 
        
             
        
        
        
Answer:
Adding sodium to chlorine gas will produce table salt.  The formation of a new substance shows that both physical and chemical change occurred.
Explanation:
The major reason why it has to be both physical and chemical is because there are some physical features that would change such as weight, appearance, color among others while the chemical properties would have changed immediately the addition occur
 
        
             
        
        
        
Answer:Robert Hooke
Explanation:The cell was first discovered and named by Robert Hooke in 1665. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. However what Hooke actually saw was the dead cell walls of plant cells (cork) as it appeared under the microscope