Answer:
The color of skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis.
 
        
             
        
        
        
A - Salinity because salinity is how much salt is in water and adding more would increase the salinity.
        
                    
             
        
        
        
Your answer would A insects because insects are the only invertebrates that can maintain flight. FOr example Butterflies and Flies Can maintain flight
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If the prey is not getting enough food, they will eventually die which affects the number of predators because then the predator species would also die