Answer:
Air, water life without these is nothing 
 
        
                    
             
        
        
        
He demonstrated that SCD and sickle cell trait were due to the presence of abnormal 8-globin polypeptides in red blood cells. He demonstrated that the electrophhoretic mobility of B-globin from patients with SCD was different from that of healthy individuals. He demonstrated that both parents of multiple patients with SCD had low levels of sickled red blood cells. He hypothesized that SCD was a recessive trait and that the parents of patients with SCD would be heterozygous carriers. He demonstrated that the difference between B-globin polypeptides in individuals who were healthy and those with SCD is an amino acid substitution. He performed a peptide fingerprint analysis on B-globin from individuals with 84 84 and 89 88, which identified the segment of B-globin that was changed by the BS mutation. James Neel Linus Pauling Vernon Ingram
hope it helps..
 
        
             
        
        
        
Answer:
Explanation:
The cell membrane separates the cell from the outer environment. The extracellular fluid contains the sodium ions (Na+), chloride ions (Cl-), while intracellular fluid contains potassium (K +) and negative anions.
The potential difference arises when the membrane is selectively permeable to some ions. The resting potential is -70mV.  
When the neurons get excited, the sodium ions start to enter by sodium channels.  
Now there are more positive ions inside the cell membrane. It disturbs the resting potential i.e. -70mV. This stage is known as depolarization.
When the inside environment of the cell is more positively charged, the potassium ions start to move out of the cell. It goes out by the voltage-gated channels. Thus resting stage is maintained and it is known as repolarization.
But the initial stability of the cell membrane has to be maintained. To restore the resting stage, the sodium ions start to move out of the membrane and potassium ions enter into the cells again. This is an active transport and has done by the Na+ - K+ pump. Here 3 sodium ions move out and 2  potassium ions pumped into the cell through the plasma membrane.  
Thus the resting potential regains. The potassium ions come back into the cells against the concentration gradient and ATP provides the energy for this phenomena.
 
        
                    
             
        
        
        
Answer:
The correct option is A)  It is not written by an authority
Explanation:
In the English language, credibility can be described as the quality of an object to be reliable or trusted. 
A piece of written work which does not mention the name of the writer may be considered to be not reliable and trustworthy. Hence, the correct option is A.
Other options, like option D, is not correct because a peer- reviewed journal carries authentic information as the work has been rechecked by different people who have expertise on the subject.