Answer:
The hydrogen bonds between water molecules
Explanation:
 
        
                    
             
        
        
        
Answer; 
A bottleneck effect
Explanation; 
When only a few individuals survive unfavorable times, thereby losing the majority of genotypes in the next generation, it is called a bottleneck effect. 
It occurs when there is a disaster of some sort that reduces a population to a small handful, which rarely represents the actual genetic makeup of the initial population.
 
        
             
        
        
        
Between the 6th and 21st days of the menstrual cycle