Answer:
Answer is Sinoatrial node, SA.
Explanation:
The sinoatrial node, SA, is known to be a group of cells which are found at the top of the heart. 
The electrical signal that is initiated by the sinoatrial node bring about or stimulates the atria and then the ventricle of the heart.
It should be noted that, the sinoatrial node are regarded as the pacemaker cells.
 
        
             
        
        
        
Answer:
An increase in the amount of CO2 well increase the rate of photosynthesis, Carbon dioxide concentration will directly affect the rate of photosynthesis as it is used in the photosynthesis reaction.Increased amount of CO2 will increase the rate of photosynthesis to a certain limit, after which a further increase in its amount will no longer increase the rate any further. This is when the other factors necessary for photosynthesis, such as light, become "limiting reactants"; that is, those other factors also need to increase to bring about a further increase in the rate.
six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen
An increase in the amount of water leads to the increase in the amount of photosynthesis
The amount of water available to the plant will affect the rate of photosynthesis. If the plant does not have enough water, the plant's stomata will shut and the plant will be deprived of CO², and thus lower photosynthesis rate.
An increase in the amount of light well increase the amount of photosynthesis, if the light intensity increases the rate of the reaction will increase at a proportional rate until a certain level is reached, the rate of increases will then go down.
Other factors affecting the rate of photosynthesis :
1. Temperature
2. The availability of nutrients
Explanation:
 
        
             
        
        
        
The nurse should reassure the patient will receive the best
care in keeping with his written directives Cardiac dysrhythmias associated
with altered myocardial automaticity, conductivity or contractility can effect
cardiac output. Reduced cardiac output increases the risk of ineffective tissue
perfusion. If the dysrhythmia is a life-threatening type, encourage the family
unit to calmly formulate a plan of action. 
 
        
             
        
        
        
1) A
2) B
3) B
4) C
5) B
6) C
7) D
8) B
9) A
10) A