Answer:
A. What causes some people to be color-blind?
Explanation:
This is something that could be tested with different variables including DNA, or past family medical history.
 
        
             
        
        
        
Answer:
I am so sorry if this is too late but your answer is in the explanation. 
Explanation:
Weakness and nausea are the responses of vomiting and fever. Because people tend to feel weak and uneasy after vomiting. Body temperature also increases resulting headache and body cramp.
        The stimulus that causes he response is coldness and weakness. And the purpose of the response of a fever is that it raises the body temperatures so that the bacteria and germs that causes the fever get kill or destroy that are sensitive to temperature changes.
 
        
             
        
        
        
I'm sorry but can you be a bit more specific on these following observations?
        
                    
             
        
        
        
At the end of the winter they are most numerous in fresh water. they will cover surface of aquatic plants or poles and wooden borders of ponds. If you like to study them you can scrape the brown growth with a flat piece of plastic. you can also use a sponge. for the free living (plankton) species fine mesh plankton net is very useful.
        
             
        
        
        
Answer:begins without any further replication of the chromosomes. the nuclear envelope breaks down and the spindle apparatus forms
Explanation: