Since it is the hearts job to pump blood throughout the body of the organism, the circulatory system would fail and the entire organism would suffer if the heart cells stopped working properly.
        
             
        
        
        
Answer:
B. separating strands of DNA
 
        
                    
             
        
        
        
Answer:
Measure only daytime.
Explanation:
It is useless to measure the oxygen production every hour for 24 hours because oxygen is produced during day time due to the presence of photosynthesis process. Oxygen is produced in large amount during photosynthesis, some oxygen is used in respiration while the remaining diffuse out from plant body through stomata. After vanishing sunlight, the photosynthesis process stop and no production of oxygen occur. So only measure oxygen production at daytime as compared to every hour for 24 hours.
 
        
             
        
        
        
Answer:
B. into an aquifer 
Explanation:
People can obtain groundwater by drilling a well into an aquifer. 
An aquifer is a porous and permeable formation where groundwater can be found. 
- Aquifer is usually found below the water table. 
- In this regard, the pore spaces of this layer of the earth allows for the storage of ground water. 
- When the aquifer is punctured, groundwater can be abstracted.