1.6 Mutations - alunga20/Concepts_of_Molecular_Biology GitHub Wiki

  • A mutation is a change in a DNA sequence. They can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.

  • Alterations occur in the nucleotide sequence of the genome of an organism, virus or extrachromosomal DNA.

  • Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis or meiosis or other DNA damages.

  • May or May not produce detectable changes in the observable characteristics of an organism.

  • Mutations play a part in both normal and abnormal biological processes i.e evolution and cancer, development of the immune system.

  • It is the ultimate score of genetic variation.

Four classes of Mutations are..

  1. Spontaneous Mutations(molecular decay)
  2. Mutations due to error-prone replication bypass of naturally occurring DNA damage.
  3. Errors introduced by DNA damage.
  4. Induced mutations caused by Mutagens. Scientists may also deliberately introduce mutant sequences through DNA manipulation.