Answer:
Somatic hypermutation is a process in which point mutations build up in the antibody V-regions of both the heavy and light chains.
This process occurs at rates that are about 106-fold higher than the background mutation rates observed in other genes.
It allows B cells to mutate the genes that they use to produce antibodies. This then ensures the B cells to produce antibodies that are better able to bind to bacteria, viruses and other infections.
 
        
             
        
        
        
Natural selection refers to the phenomenon by which the species in a population possessing the tendency to get adapted in a condition enhance in numbers in comparison to those who exhibit fewer adaptation capacities over a number of generations.  
In other words, it can be stated as the non-random and differential development of distinct genotypes function to sustain favorable variant and to eradicate less favorable variants. Some of the conditions are required for the process of natural selection to take place.  
These are heredity, reproduction, variation in individual characters, and variation in the fitness of organisms among the members of the population. If the conditions are met, then the phenomenon of natural selection occurs by default.  
 
        
             
        
        
        
Answer:
diverse proteins embedded in a phospholipid bilayer
Explanation:
According to fluid mosaic model the cell membrane is made of bilayer of phospholipid. Many proteins are embedded in this bi layer. Carbohydrate and cholesterol are also found in different forms. Carbohydrate can either be attached to the embedded protein in which case it is called as glycoprotein or it can be connected to the lipid molecule in layer and called as glycolipid. 
Proteins can be found in two forms too. They can either be embedded in the layer i.e. they can penetrate single or both layers. These proteins are called as integral proteins. They can also be present on one side of the membrane and not penetrate the lipid bilayer in which case they are called as peripheral proteins. 
 
        
             
        
        
        
Matrix are within the inner membrane of the mitochondria.