the three general classifications are sensory neurons, motor neurons and interneurons. I don't know how they work together to produce a response to an environmental stimulus:( sorry
        
             
        
        
        
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Answer: an animal that is hunted and killed by another for food.
Explanation:
 
        
                    
             
        
        
        
Answer; 
Retinohypothalamic path
A small branch of the optic nerve, known as the retinohypothalamic path extends directly from the retina to the SCN.
Explanation;
The SCN is an abbreviations for suprachiasmatic nucleus or nuclei; which is a region in the hypothalamus. that is responsible for controlling circadian rhythms. 
Retinohypothalamic path is a neural input pathway that extends directly from the retina to the SCN.