Nature of Mutations

Nature of Mutations

Mutations can originate in a number of ways. For example, during the DNA duplication process, an organic base may be paired incorrectly within the newly forming strand, or some extra organic bases, may be built into its structure. In other instances, sections of DNA strands may be deleted, moved to other regions of the molecule, or even attached to other chromosomes. In any case, the consequences are similar: the genetic information is changed, and if a protein is constructed from this information, its molecular structure is likely to be faulty and the protein nonfunctional. 

Fortunately, cells can detect damage in their DNA molecules, and they possess enzymes that often can repair damage occurring in a single strand of DNA. These repair enzymes are able to clip out defective nucleotides and cause the resulting gap to be filled with nucleotides complimentary to those on the remaining strand of DNA. In this way, the original structure of the double-stranded molecule can be restored.

On the other hand, both strands of the DNA molecule may be damaged in the same region This type of change is unlikely- to be repaired, and if the cell survives and reproduces, its daughter cells are likely to receive copies of the mutation.