Answer:
The DNA is a double helix or made up of two strands. The strands are separated during replication, each serving as a template to produce a complementary strand of each of the separated single strands. Therefore after replication, two double stranded DNA molecules will be present.
 
        
             
        
        
        
Explanation:
While exercising, the muscles need additional energy as the breathing rate and volume of each breath increases to bring more oxygen into the body and remove the carbon dioxide produced. The heart rate increases to supply the muscles with extra oxygen and remove the carbon dioxide produced.