The most observable difference is the way in which cytokinesis occurs. In plants a new cell wall is fashioned between the new daughter cells, while in animal cells the cell membrane constricts to pinch the parent cell into daughter cells.
        
             
        
        
        
Answer:
B. So you can always see the entire object at the higher magnification
Explanation:
A microscope is used to view objects smaller than the naked or unaided eyes can see. The objective lens, in conjunction with the occular or eye lens, is used to achieve this purpose. The objective lens are of different magnifications as follows: 10X, 40X, 100X etc. 
However, as the magnification increases i.e. higher objective, the object in the field of view becomes smaller and less focused. Hence, the object in the field of view must first be centered at a lower magnification/objective lens before changing to a higher one in order for the entire object to be seen at a higher magnification. 
 
        
             
        
        
        
heart, arteries, and veins
 
        
             
        
        
        
The Griffith's experiment, the Avery-MacLeod-McCarty experiment, and the  Hershey–Chase experiments were the set of experiments that established DNA as the key hereditary molecule. The Avery-MacLeod-McCarty experiment was an extension to the Griffith's experiment. The heat killed virulent S strain cells of the Griffith's experiment were lysed to form a supernatant containing a mix of RNA, DNA, proteins and lipids from the cell. The supernatent was equally divided into 3 parts after the removal of the lipids. The 3 parts were respectively treated with an RNAase to degrade the RNA, DNAase to degrade the DNA and proteinase to degrade the proteins. The treated supernatant was then added into the culture containing the non-virulent R cells. In case of the supernatant treated with the DNAse, no transformation of R cells into S cells occurred. The transformation of R cells to S cells occurred in the proteinase and the RNAse cases. This indicated that DNA was the hereditary molecule and not protein or RNA. 
