This question would be better placed under the Chemestry section
        
             
        
        
        
A CELL WALL because the other three appear in different types of cells
        
                    
             
        
        
        
Answer:
Bipedal posture allowed arms to be free to develop and use tools.
Explanation:
 
        
                    
             
        
        
        
Answer:
The enzyme function best at a specific temperature. 
Explanation:
Enzyme activity is affected by temperature. Each enzyme has a specific temperature
range in which it works most effectively. Most biological enzymes present in the human  body have an ideal temperature range of around 98.6 degrees.