Mutations There are different types of mutations, some may be harmful, helpful or neutral: Point mutation: it is a change in one or just a few nucleotide in the code. Frameshift mutation: it is deletion or insertion that causes the reading frame on the remaining nucleotides to be shifted over and read incorrectly. Substitution: one nucleotide in code is replaced by another. Polypoidy: complete set of chromosomes fails to seperate resulting in 3N or 4N organisms. Deletion: piece of DNA is broken off and lost. Translocation: piece of DNA breaks off and reattaches to another NON-homologous chromosomes. Inversion: piece of DNA breaks off, flips, snd reattaches so that it reads backwards. Insertion: piece of DNA is added to the code. Duplication: extra copies of parts of a chromosome are made.