Answer:
a variety of genes are involved in the control of cell growth and division. the cell replicates itself in an organized, step by step fashion known as the cell cycle. 
Explanation:
tight regulation of this process ensures a dividing cell's DNA is copied properly, any errors in the DNA are repaired and each daughter cell receives a full set of chromosomes. 
 
        
             
        
        
        
A shark's cardiovascular system flows in one loop, called the double circulatory system. Where as with mammals it is more like a tree, veins branching out from the heart and off other blood vessels.