Explanation:
white blood cells are the cells that do not have any shape
 
        
                    
             
        
        
        
Answer:
The correct answer will be option-C
Explanation:
The rhythm of the heartbeat is controlled by the pacemaker of the heart called the sino-atrial node.
The SA node generates action potentials which trigger the contraction and relaxation of the atrium and ventricles. The membrane potential generation initiates by the depolarization of the cell membrane when the L type of Ca⁺² ions opens up and calcium ions enter the cell.
This depolarizes the cell until the potential threshold is reached which lies between the -40 and -30 mV.
Thus, Option-C is the correct answer.
 
        
             
        
        
        
By taking daily antibiotics, people are encouraging resistance by getting their immune systems used to the formulas. Antibiotic resistance<span> occurs when bacteria change in a way that reduces the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply, causing more harm. I think that people can help by not taking antibiotics for every little pain they have, instead try other simple remedies and only use medicines in cases where other remedies won't help. </span>
        
             
        
        
        
Once this initial energy is added, the wave travels through the medium until all its energy is transferred. In contrast, electromagnetic waves require no medium, but can still travel through one.