Assertion: nucleotide | /r/HasProperty | substituted
Facets:
Source sentences:
text: A nonsense mutation occurs when one nucleotide is substituted and this leads to the formation of a stop codon instead of a codon that codes for an amino acid.
text: Like a nonsense mutation, a missense mutation occurs when one nucleotide is substituted and a different codon is formed; but this time, the codon that forms is not a stop codon.