Answer is B since it uses strains and differential transformation to see
        
             
        
        
        
Answer:
A) they help transport some substances through the membrane. 
Explanation:
The membrane proteins that span the bilayer of phospholipids help in the transport of polar, large and charged substances across the membrane. The nonpolar core of the membrane does not allow these charged and polar substances to pass through. Proteins serving as channels form pores to allow movement of the specific substances.  
On the other hand, carrier transport proteins of the membrane bind to the substances present at one side of the membrane and deliver them to the opposite side.
 
        
             
        
        
        
"D: A new gene, which codes for the protein that can repair defective genes, is introduced."
Explanation: <span>Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery.</span>
        
                    
             
        
        
        
If the amount of leaves on a tree decreases, the number of bird nest will decrease, because birds build their nest on leaves of a tree....Am ebube Slt