These structures are called Vestigial structures, they resemble structures from the organism's ancestors, but don't have a real purpose for them now. 
Pray this helps you :)
        
                    
             
        
        
        
All the trophic levels are there, Number ten is asking you to find a chain that includes 7 organisms. Starting from:
Phytoplankton (Producer)
Herbivorous Zooplankton (Primary Consumer)
Carnivorous Zooplankton (Primary Con.)
Artic Char (secondary Con.)
Capelin (tertiary Con.)
Harbor Seal (Quaternary Con.)
Polar Bear(Quaternary Con.)
 
        
        
        
Answer:
O The Green revolution has caused a decrease in energy production.
O The Green revolution has led to many people dying of hunger
Explanation:
 
        
             
        
        
        
Mercury's seasons are difficult to determine. This is because it has virtually no tilt (0.03 degrees), but a highly elliptic orbit. ... Mercury also has a bizarre rotation, spinning three times (every 53 Earth days) over two rotations around the Sun, making it impossible to tell when one season begins and one ends.
        
             
        
        
        
Answer:
The synthesis of new proteins