Elephants, who are important grazers, are instrumental in transforming woodlands into grasslands. This has a tremendous impact on other species that depend on the grass for their survival. The significance of the elephant in this example is B. keystone species. 
        
                    
             
        
        
        
When our red-sensitive nerves in our eyes cannot respond to light properly this will result in color blindness - b. 
When either of the three light-sensitive nerves in our nerve tracts; either green, red or blue, we become to color blind for a certain spectrum of light from nature. 
        
             
        
        
        
Answer:
Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment. Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface.
Explanation:
Hope that helps:)
 
        
             
        
        
        
Answer:
Channel proteins form hydrophilic channels to passively transport substances down the concentration gradient.
Carrier proteins bind to substances to transport them actively against the concentration gradient. They do not form channels.
Explanation:
Channel proteins are the membrane proteins that serve in transport of small polar molecules and/or ions by making a hydrophilic pore across the membrane. These molecules diffusion through the pore and exhibit facilitated diffusion.  
Carrier proteins are the membrane proteins that transport the substances across the membrane by binding to them. They do not form the hydrophilic channels. Carrier proteins serve in the active transport of molecules against the concentration gradient.
 
        
             
        
        
        
C. The lynx population crashes due to their food source being gone.