Viruses enter human body like an invader and uses the living cells to replicate causing infections in the cell or can damage it.
Explanation:
The attacks of viruses on the body of living organisms is compared with a ‘sneak attack’ as they invade the body and enters into a living cell to replicate themselves. This may cause damage or bring about changes in the cell causing sickness and infections. 
They can hide themselves on our body attacking sneakily to harm the immune system to fight the infection. This stealth infection can result in fever, damaging immunity, disorder etc.
 
        
             
        
        
        
Ok this might not be the best answer but just by reading it, it may be unreliable because numbers do change over time
        
                    
             
        
        
        
Answer:
A noncurler has a genotype cc.
Explanation:
If curlers always have at least one curler parent, it is possible being "curler" will be related to a dominant allele, in this example, "C".  So, being "noncurler" could be a recessive trait. Noncurler can have one or both parents who are curlers, and this is concordant with a recessive inheritance if both parents are heterozygous (Cc) (with a probability of 25% of being "noncurler"). Also, it is possible if one parent is heterozygous and the other is homozygous for c (Cc x cc), this with a probability of 50% ob being "noncurler".  
The Punnett square shows this clearly. 
 
        
             
        
        
        
 D has a positive charge and located in nucleus