Fact 1: Mutations may change the structure of a chromosome or just change a single nucleotide.

Fact 2: Mutagenic chemicals cause mutations.

Given the two facts above, answer the question "What may change the structure of a nucleotide?" with the following options: 
- oxidation reaction
 - adding heat
 - Water
 - Name
 - Mutagenic chemicals
 - permineralization
 - Air
 - that material's properties


 

     Mutagenic chemicals    