Answer:
One band of light density and one band of heavy density.
Explanation:
According to conservative model of replication, the original strands do not separate from each other during replication. Hence, after replication the old strands are together and the new strands are together.
Here, cells were grown in 14N medium first so 14N was used for DNA replication and all DNA molecules had 14N. When the cells were transferred to 15N medium, only 15N was available for replication process. New DNA molecules would be synthesised using 15N (15N15N) and old DNA molecules have 14N (14N14N). Hence, in density gradient one band will be of light density (14N14N) and one band will be of heavy density (15N15N). 
 
        
             
        
        
        
C because our bodys are mixing chemicals 
        
             
        
        
        
Answer:
4.Cell wall protects the cell whiles organelles are found in the cell itself which is having the cell wall
 
        
                    
             
        
        
        
Answer:
a structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules
Explanation:
Kinetochores have  vvery important role in the cell division-mitosis.
During the metaphase of mitosis, spindle fibers attach to kinetochores. Some of the microtubules bind to kinetochore (kinetochore microtubules) while other don’t: they connect with the microtubules from the opposite pole, stabilizing the spindle.
 During the anaphase, kinetochore microtubules pull chromosomes toward poles, helping the sister chromatids separate from each other.  
 
        
             
        
        
        
The percentage is 89%. Took this test and got the same exact question.