Answer:
Oxygen atoms contain 16 times more mass than Hydrogen atoms.
(a brainliest would be appreciated)
        
             
        
        
        
The basic unit of life is cell(s).
        
                    
             
        
        
        
1. Two genetically identical copies of DNA 
2. Finds an error in DNA, removes the incorrect nucleotide and replaces it with a correct one.
3. It is used as a copy/ "template" for replication in order to have two identical copies of DNA.
4. DNA helicase unwinds DNA double helix and Topiosomerase ensure there isn't too much unwinding.
5. Replication has a built on proofreading system - DNA polymerase removes the incorrect nucleotide and replaces it with a correct one.
        
             
        
        
        
Answer:
ZBWCYAX
Explanation:
Equation for the intermediates: Z↔W↔Y↔X
1) B catalyzes the breakdown of Z, therefore inhibiting B leads to the build up of Z.
2) If enzyme C is inactive then the organism will not  receive Y to grow, thus Y is a by-product of C.
3) If A is inhibited then W, Y and Z build except for X, thus it make sense that A catalyzes a reaction that leads to X as a by-product.
4) Inhibiting C leads to the reaction toward making Z and W, thus it catalyzes the breakdown of C directly and Z indirectly.