Mutation

• Mutation


  Random changes in the sequence of bases in DNA
• Mutagenesis


  The process by which the genetic information of an organism is changed by the production of a mutation
• Mutagens


  Agents that cause alteration in the DNA
• Types of Mutagens


  • Physical Mutagens (x-rays, gamma rays, sunlight, photons)
  • Chemical Mutagens (alkaline, analogs, molecules, water, fluids)
  • Biological Mutagens (bacteria, fungus, prokaryotes, microorganisms)
• Point Mutation


  A type of mutation in DNA or RNA wherein one single nucleotide base is substituted
• Point mutation


  Can lead to SUBSTITUTION mutation
• Silent Mutation


  Happens when a nitrogenous base is altered but the same amino acid is produced
• Missense Mutation


  When one nitrogenous base of the DNA is replaced, and the result is an altered codon but does not form a stop codon
• Types of Missense Mutation

  • Conservative Mutation
  • Non-conservative Mutation
• Conservative Mutation


  When a new amino acid is formed, it has the same properties as the one that was supposed to be produced
• Non-conservative Mutation


  When a new amino acid is formed, it has properties different from what was supposed to be produced
• Nonsense Mutation


  Nonsense mutation results in the formation of a stop codon due to the substitution of one nitrogenous base
• Frameshift Mutation


  A deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence
• Types of Frameshift Mutation

  • Deletion
  • Insertion
  • Duplication
  • Inversion
  • Translocation
• Deletion


  The removal of one or more bases
• Insertion


  The addition of one or more bases
• Duplication


  A codon or set of bases is duplicated
• Inversion


  A codon or the entire RNA is inverted
• Translocation


  A codon or bases are transferred to another nucleic acid
• Sickle Cell Disease


  • Happens when Valine substitutes glutamic acid
• Albinism (type 1 Oculocutaneous Albinism)

  • Caused by deletion mutation (deletion of tyrosinase)
• Cystic Fibrosis


  • Caused by deletion mutation (deletion of phenylalanine)
• Down Syndrome or Trisomy 21


  • Caused by translocation during meiosis that transfers most of chromosome 21 onto chromosome 14