Explanation:
The 47,XXY karyotype of Klinefelter syndrome spontaneously arises when paired X chromosomes fail to separate (nondisjunction in stage I or II of meiosis, during oogenesis or spermatogenesis
 
        
             
        
        
        
Archaebacteria are called ancient bacteria whereas eubacteria are called true bacteria. Unlike eubacteria, archaebacteria can survive in extreme conditions.
        
                    
             
        
        
        
Answer:
D. The two students who have two fragments have one restriction site in this region.
Explanation:
The DNA samples from the cheek cells were subjected to digestion with a restriction enzyme. This enzyme is an endonuclease and cuts the DNA at a specific sequence only. This sequence is called a restriction site. If the restriction site is not present in the sample DNA, the restriction enzyme cannot cut it. The presence of one restriction site in the sample DNA would cut it into two DNA fragments. 
Similarly, the presence of two restriction sites in each DNA molecule would obtain a total of three DNA fragments per DNA molecule.
 
        
             
        
        
        
Answer:
It depends on your test scores.
Explanation: