C) White light is least useful for photosynthesis in terrestrial plants. Green would be more useful because that's their usual color. 
        
             
        
        
        
The correct answer is Karl will get sick and Jose will not this time, but neither will get this influenza again since they both will have acquired active immunity to it.
In the case of Jose artificially active immunity has been induced due to vaccination. A vaccine instigates a primary response against the antigen without resulting in any signs of the disease. On the other hand, Karl will acquire active immunity naturally in future, as when an individual get exposed to a live pathogen, he or she develops the disease, and turns immune as an outcome of the primary immune response.  
 
        
                    
             
        
        
        
The effect of chemical pollution on insects living in a pond i think
        
             
        
        
        
Answer:
<h3>Biologists study humans, plants, animals, and the environments in which they live. They may conduct their studies--human medical research, plant research, animal research, environmental system research--at the cellular level or the ecosystem level or anywhere in between.</h3>