Answer:
the chromosome are found in the nucleus of a body cell in pair
 
        
             
        
        
        
Answer:
Well one of the types of symbiosis is parasitism. Here an example would be a tapeworm (parasite) would live in and feed off a living host (humans in our case)
Explanation:
 
        
             
        
        
        
The main reason for the difference in the mass extinction occurring today and previously is the pace of the current extinction. The extinction is taking place globally and involves hundreds of species at the same time. In less than 50 years, we have lost numerous species. In contrast to this, previously during the mass extinction, only a few species were lost, and other managed to survive. But, not the status is opposite due to the magnitude of the extinction. 
        
                    
             
        
        
        
Explanation:
After repeated stimulation by antigen, B cells can make antibodies that bind their antigen with much higher affinity a process called affinity maturation. ... Thus, antigen stimulation greatly increases the antibody arsenal. Antibodies are proteins, and proteins are encoded by genes.
 
        
                    
             
        
        
        
to rech the sunlight for food or nurishments