A sudden shift in the tectonic plates of the earth
        
                    
             
        
        
        
The answer to the 3rd question is that chromosomes are tightly coiled bundles of DNA and carry many genes. For the 4th question, asexual reproduction can occur by binary fission and creates exact genetic copies of a parent. 
        
                    
             
        
        
        
Answer:
The average trait value changed in one direction.(In this case, larger size)
Explanation:
In evolution a natural selection can be disruptive, directional or stabilizing
In stabilizing no extreme trait is favored hence provides intermediate values .
Disruptive selection both extreme traits are favored over the intermediate trait.
Directional, the enviroment will favor the survival of one trait hence a change in direction either towards the left or the right.
In the case of swallow cliff mortality, selection favored the larger size.
 
        
             
        
        
        
The overall goal of IPM is to reduce the environmental and health risks of pesticides within social and economic constraints.
Fix: The scope of IPM implementation will continue to change greatly in the future. What began as limited approaches to promote integration of control methods for key pests and provide guidelines for decisions regarding pesticide applications is evolving to an ecologically-based systems approach.
 
        
             
        
        
        
The second option is the best answer.
Proteins are complex polymers of amino acids. They are folded into 3 dimensional structures . This folding defines not only the size and shape of the protein, but also its function.
The folding of a protein allows for interactions between amino acids that may be distant from each other in the primary  sequence of the protein. In enzymes, some of these amino acids form a site in the structure that catalyzes the enzymatic reaction. This site is called the active site.