Answer:
Stomata
Explanation:
Normally stomata open when the light strikes the leaf in the morning and close during the night.
 
        
                    
             
        
        
        
Answer:
A option
Explanation:
Guard cells closes their openings to prevent loss of water, hence, slowing down the process of transpiration.
<em>Hope</em><em> </em><em>it</em><em> </em><em>helps</em><em>.</em>
 
        
                    
             
        
        
        
She was unconscious before the incident so something must have happened before it, also the bruise could result in brain damage.
        
             
        
        
        
The Lock-and-key mechanism was first proposed by Emil Fischer which described as the enzymatic reactions whereby an enzyme with a single substrate binds temporarily to form a substrate complex.  
The lock-and-key mechanism is usually associated with the complementary shapes of an enzyme with a single substrate, wherein the lock  that is being referred to is the enzyme and the substrate is the key. One right sized substrate (key) fits into the active site (key hole) of the enzyme (lock). 
The active site which is mentioned above is structurally complementary to the substrate. This is the temporary binding site on the enzymes. Just like a lock and key, the enzyme as the lock and the substrate as the key is said to fit together.