Diploid cells contain 2 sets of the same DNA where as haploid contains one set.....so our normal cells in our body (somatic cells) are diploid however our sex cells(gametic cells) which are the egg of a woman and sperm from a guy are only haploid which means they have only 1 copy of DNA......this is because they fuse with one another and add their DNA together to make a diploid cell
        
                    
             
        
        
        
During fertilization, a _sperm_ and _egg_ combine to form a _zygote_. 
Sperm and egg (gametes) are both haploid, and the fertilized zygote is diploid.
        
             
        
        
        
That is called A. <span>Circular distribution.</span>
        
             
        
        
        
In the DNA, that is why they are called the building blocks of life.