DNA mutation

• What is the definition of a mutation?

  A change in the DNA base sequence
• What can cause mutations in DNA?

  Carcinogens and certain types of radiation
• When do mutations happen spontaneously?

  During DNA duplication before cell division
• Do carcinogens always cause mutations?

  No, they increase the risk of mutations
• What is a triplet or codon?

  A group of 3 bases coding for an amino acid
• What happens if a codon changes due to a mutation?

  The amino acid it codes for may change
• What can happen to an enzyme if a mutation occurs?

  Its active site may change shape
• What is the most common effect of mutations?

  They often have no significant effect
• Why is non-coding DNA important?

  It plays a role in gene expression
• What are the three specific types of mutations?

  Substitutions, insertions, and deletions
• What is a substitution mutation?

  One base is changed for another base
• Why are insertion mutations more severe than substitutions?

  They shift all subsequent bases along
• What happens during a deletion mutation?

  One base is removed from the sequence
• If a T is deleted from a DNA sequence, what happens?

  All subsequent bases shift left
• How do different types of mutations affect DNA sequences?

  • Substitution: One base changes
  • Insertion: Extra base added, shifts sequence
  • Deletion: Base removed, shifts sequence left