Answer:
1. Purines
2. States that DNA composition varies among species
3. Hydrogen Bond
4. Purines
<em>Answer to #2 is a little iffy </em>-- sorry
Explanation:
Pyrmidines have two rings
Purines have one ring
Complementary bases are connected by hydrogen bonds.
 
        
             
        
        
        
Answer:
A-color
Explanation:
Minerals could have the same color, and you can't depend on color to tell you that.
 
        
                    
             
        
        
        
Answer:
The enzyme responsible for separating the two strands of DNA in a helix so that they can be copied during DNA replication.Explanation:
 
        
             
        
        
        
Cyanobacteria released OXYGEN into the atmosphere through photosynthesis