I believe the biosphere is fragile, because over time all of the pollution us humans have made; If its from air pulloution, acid rain or even water pollution. the toxic acids over time have made the biosphere and the ozon layer weaker and more thin. which causes the biosphere to become weaker.
        
                    
             
        
        
        
Either A. or D. it depends on what kind of insulation you're looking for.
        
             
        
        
        
Answer: map
Explanation: I say its map because a map represents the entire earth
 
        
                    
             
        
        
        
Answer:
The solution was hypertonic and that the cells had burst. 
Explanation:
 
        
             
        
        
        
Answer:
Enzymes function best at specific pH and temperatures. 
Explanation:
An enzyme can be defined as a biological catalyst that typically lowers the activation energy of a biological reaction. When the activation energy of a reaction is low, the rate of the reaction would be faster. Therefore, an enzyme speeds or catalyzes the rate of a reaction by lowering its activation energy. 
Also, if the conditions are not optimal for an enzyme, it limits the ability of an enzyme to bind or be joined with its substrates. 
Hence, the correct statement about enzymes is that enzymes function best at specific pH and temperatures. An increase in temperature increases or speeds up the rate of a reaction while low temperature limits or reduces the rate of a reaction. The optimal temperature for enzymes in the human body is around 37 degrees celsius.