D. This is to “proofread” the DNA
        
                    
             
        
        
        
Answer:
photosynthesis process uses the sun's energy to combine carbon dioxide and water to form glucose, a sugar. Carbon dioxide enters plants through tiny pores in the bottoms of leaves or by diffusion through cell membranes in the case of algae and protists.
 
        
             
        
        
        
Functional groups are a group of molecules attached to a carbon-based core of an organic molecule. Key functional groups are 3. phosphates
 
        
                    
             
        
        
        
Answer:
The answer should be C
Explanation:
If you look at the the graph, C points to the time period after mammals appeared. Since birds are mammals, they should have appeared after the time that mammals first came to be on Earth. 
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