Answer:
D: They have restricted cell division. 
Explanation:
Pre cancerous cells often act like cancer cells and will grow at abnormal rates but unlike cancer cells they are unable to invade other organs 
 
        
             
        
        
        
A star's brightness is determined by the distance away from earth.
        
             
        
        
        
Answer:
because the blood in the heart gets what's left of oxygenated blood first. first come first serve concept. the heart cells survive longer because they have oxygenated blood longer and more frequently. if the person is not breathing the oxygen in the blood might run out by transferring to cardiovascular cells before it gets to the brain.
Explanation:
 
        
             
        
        
        
The option are not given and the options are:
Proteins are denatured by breaking covalent bonds.
Linear molecules like DNA are inherently stable.  
Individual hydrogen bonds may be weak, but DNA structure is stabilized by many thousands or millions of these bonds - far more than found in proteins.
The statement is incorrect; it actually takes far more energy to denature proteins than it does to denature DNA.
Answer:
The correct answer is- Individual hydrogen bonds may be weak, but DNA structure is stabilized by many thousands or millions of these bonds - far more than found in proteins.
Explanation:
Proteins become denatured when it looses its three-dimensional structure. Disulfide bond and hydrogen helps in stabilizing the three-dimensional structure of proteins and if these bonds break due to any factor protein lost its structure and function.
DNA is made up of a large amount of hydrogen bond because in AT base-pairing two hydrogen bonds are required and in GC base pairing three hydrogen bonds are required. Therefore it can be concluded that as more hydrogen bonds stabilizes DNA than protein its melting temperature is higher than protein.