Another type of mutation is a frameshift mutation which is caused by the insertion or a deletion of a base pair. An inserted or deleted nucleotide alters the triplet grouping of nucleotides into codons and shifts the reading frame so that all nucleotides downstream from the mutation will be improperly grouped. The result is a protein with extensive missense ending sooner or later in nonsense. Mutagens A mutation can be the result of different events. Errors made during replication, repair, or recombination can all lead to point or frameshift mutations.
Mutations resulting from such errors are spontaneous mutations.
A mutation can also result from the action of physical and chemical agents known as mutagens. Nitrous Acid affects DNA complementation. The acid randomly modifies the base adenine so that it will pair with cytosine instead of thymine. This change is made evident during DNA replication when a new base pair appears in daughter cells in a later generation. A base analog is a compound sufficiently similar to one of the four DNA bases but have different pairing properties.