Mutation

• mutation


  any change in the quantity or the base sequence of DNA
• gene mutation

  any change to one or more nucleotide bases or change in the sequence of bases in DNA
• Substitution of bases

  The type of gene mutation in which a nucleotide in a DNA molecule is replaced by another nucleotide that has a different base
• Deletion of bases (addition/insertion)


  when a nucleotide is lost from the normal DNA sequence
• Chromosome mutations

  • Changes in the whole sets of chromosomes → polyploidy
  • Changes in the number of individual chromosomes → non-distjunction
• Effects of mutations in DNA

  • Base sequence of DNA is changed
  • Different sequences of bases in mRNA
  • Attracts different tRNA/anti-codon
  • Different amino acids inserted into protein/polypeptide
  • May affect tertiary structure of protein