Active transport is the movement of molecules against the concentration gradient from an area of high concentration to an area of low concentration, which requires energy in the form of ATP. Hope this helps! ^.^
        
                    
             
        
        
        
One fourth means (one half) of (one half) .
So the 18 months must be two half-lifes.
The half-life of this particular isotope is 9 months.
        
             
        
        
        
-0.5m/s^2
Explanation:
the answer is negative this only show direction that is acceleration is a vector quantity 
 
        
             
        
        
        
"They are <span>multicellular" is not a characteristic of bacteria. Although it should be noted that the smallest life forms don't necessarily have to be bacterial. </span>
        
             
        
        
        
Answer:
option D
Explanation:
how the plant growth will be enhanced, so it seems incorrect.