mutations

• • a mutation is random change in organism's DNA
• • mutations occur continuously
  • can occur spontateously
  • when chromosome isn't replicated properly
  • chance of mutation can increase by exposure to radiation
• • mutations change sequence of DNA bases in gene
  • genetic variant is produced
  • so, change in protein coded
  • because bases change, so amino acid changed
• • most mutations have no effect on protein
  • some mutations code for altered protein with change in shape
  • so, function changed
  • shape of enzyme active site can change, so substrate can no longer bind
  • structural protein can lose strength
• • mutation in non-coding DNA can change how genes are expressed