Choose the incorrect statement(s).
1. Intercalating agents cause primarily frameshift mutation.
2. Luria-Delbruck fluctuation test provided the first experimental evidence supporting the hypothesis that mutations occur spontaneously.
3. Tautomer is an alternative isomeric form of a base due to the movement of one hydrogen atom from one position to another.
4. Missense type of mutation results when a base substitution in a codon leads to the formation of another codon calling for the insertion of a different amino acid.