The main responsible for the delay among the atrial and
ventricular contractions is the action potential conduction velocity of the AV
node cells. If the atria and ventricles contract simultaneously, atria cannot
give any help in filling the ventricles, which is needed, especially in those
with stiff ventricles as in the elderly. Hence atria have to contract first and
then the ventricles.
 
        
             
        
        
        
Hi lovely,
The answer you're looking for would be Biosphere.
        
                    
             
        
        
        
<span>Group A beta-hemolytic streptococcal causes rheumatic carditis. The most common age group for this inflammation are children 5 through 15 years old. Symptoms include chest pain, swelling of the ankles, a fever, joint pain and a sore throat. People with this inflammation should use antibiotics to cure it.</span>
        
             
        
        
        
Why do most cells in the human body divide infrequently? They have exited the cell cycle and entered G0. The free-energy change for the oxidation of glucose to CO2 and water is -686 kcal/mol, and the free-energy change for the reduction of NAD+ to NADH is +53 kcal/mol
        
             
        
        
        
Answer:
Disaccharide
Explanation:
It is a disaccharide, a molecule composed of two monosaccharides: glucose and fructose. Sucrose is produced naturally in plants, from which table sugar is refined. It has the molecular formula C12H22011.