Answer:
I think it's B 
Explanation:
During QRS that's when the depolarization happens and when that happens the ventricles contract and push blood to the lungs and body.  
 
        
             
        
        
        
Answer:
<em>Respiration and photosynthesis. </em>
Explanation:
<em>Respiration provides the cell with oxygen while photosynthesis provides it with carbon dioxide. Both functions release what is needed for the other. Therefore, these functions interact.</em>
 
        
             
        
        
        
Answer:
In the given case, for the researcher to succeed, there is a need to place the gene next to the promoter sequence, which gets expressed in the mammary cells. The sequences of DNA, which illustrate that where the transcription of a gene by the RNA polymerase initiates is known as the promoter. These sequences are generally situated at the 5 prime terminals of the initiation site of transcription or are situated directly upstream.