Errors during DNA replication will result in mutations. Mutations are changes that can be either positive or negative. There are two examples of mutations that take place: point mutations and frameshift mutations.
A point mutation occurs when a single nucleotide changes and causes potential changes in a protein. There are three types of point mutations. They are called silent, missense, and nonsense.
Silent: DNA changes - RNA changes - Amino acid no change
Missense: DNA changes - RNA changes - Amino acid changes
Nonsense: DNA changes - RNA changes - Early stop codone
A frameshift mutation occurs when a nucleotide is either added or deleted from original DNA or RNA strands. These cause the length of the gene to be altered, ultimately creating a shift in the codone reading frame. This type of mutation results in diseases such as Tay-Sachs, which destroys nerve cells located in the brain and spinal cord.