Answer:
The options are
A. secondary structure ... hydrogen bonds
B. secondary structure ... peptide bonds
C. tertiary structure ... hydrogen bonds
D. primary structure ... covalent bonds
E. tertiary structure ... covalent bonds
THE CORRECT ANSWER IS A.
A. secondary structure ... hydrogen bonds
Explanation:
The secondary structure of a polypeptide shows the localized regions of its organised structure being upheld by hydrogen bonds among the major groups 
-NH and C = O 
At the same time, it inhibits the hydrogen bonds of the side chains from influencing the reaction process. 
The polypeptide secondary structure shows the dexterity to curl or fold as sustained by the polypeptide chains.
 
        
             
        
        
        
B. sexual selection, which alters allele frequencies in the gene pool.
        
                    
             
        
        
        
On the off chance that a change happens, if beneficial in the scarcest, normal choice picks it to wind up noticeably the more typical quality, and consequently development happens. For instance the dark demise wiped out one in three Europeans, now researchers are finding that some of the individuals who survived had transformations on their resistant framework cells; they needed regular receptors, or generally had few. (DNA resembles history, obviously, they aren't meeting with dark torment patients, the DNA in Caucasian Europeans goes about as an authentic guide of past bottlenecks.) Because Europeans with this transformation were to the least extent liable to bite the dust of the dark passing they were the well on the way to survive, which is the reason the calamity of the bubonic torment brought about somewhere in the range of 20% of Caucasian European relatives to do not have these receptors on their invulnerable framework cells which thusly diminishes the danger of resistance illnesses, for example, assistants.
        
             
        
        
        
Answer:
The fever is the immune system's attempt to kill the infection. Very rarely, however, this immune response can result in a fever high enough to cause permanent harm or even life-threatening complications due to overheating.