D is the answer. A gene is a part of a chromosome.
        
             
        
        
        
Answer:
dimerization and phosphorylation
Explanation:
Protein kinase receptors are simply saying receptors with associated kinases (usually tyrosine kinases).
Protein kinases are enzymes that have the ability to modulate other enzymes (or some other proteins) by adding the phosphate group. This is known as phosphorilation process. As a result of structural change, protein can change its activity (phosphorilation usually increase the activity). 
Such receptors are involved in a many processes within an organism that are important for the cellular growth, differentiation, metabolism .
 
        
             
        
        
        
The water level in the bucket would drop.
This is because the pebbles have a greater density than water - they displace more water (when floating in a cup), than their volume. Thus the water displaced by the cup of floating pebbles has to be more than the volume of pebbles in the cup.
 
        
             
        
        
        
I'm pretty sure it's A.<span>Evaporation decreases salinity, and heavy polar air increases atmospheric pressure.</span>