Base substitution mutations can have the following molecular consequence except: (A) Changes one codon for an amino acid into another codon for that same amino acid, (B) Codon for one amino acid is changed into a codon of another amino acid, (C) Reading frame changes downstream to the mutant site, (D) Codon for one amino acid is changed into a translation termination codon
Answer is C. Option 'a' is silent mutation, option 'b' is missense mutation, and option 'd' is nonsense mutation. All three are types of point mutation (base substitution mutation). Option 'c' is frame-shift mutation.