Bio3400 Chapter 15 Gene Mutation, DNA Repair, and Transposition
  1. A mutation is a         in DNA sequence and can occur spontaneously or be          by an external agent (mutagen).



     
     
     
     
  2.             shifts in nucleotides can result in             mutations due to anomalous base pairing.



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  3. DNA base damage by              can also lead to mutation.

     
     
     
     
  4. Other chemical mutagens include             agents which donate an alkyl group to nucleotides.



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  5. In general, base          can lead to             mutations during DNA replication.

     
     
     
     
  6.           dyes cause             mutations by intercalating between purines and pyrimidines.

     
     
     
     
  7. High energy radiation such as              (UV) light,    rays,        rays, and         rays are also mutagenic.



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  8.                repeat sequences can cause several human genetic disorders.

     
     
     
     
  9. The       test uses bacteria selected for their sensitivity to specific types of mutagenesis to screen compounds for potential mutagenicity.

     
     
     
     
  10.                  repair can restore gaps created during DNA replication due to damaged nucleotides.



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  11.                    repair in prokaryotes can remove thymine dimers caused by UV light.

     
     
     
     
  12. Two types of excision repair can also repair damaged DNA:       excision repair (BER) and             excision repair (NER).



     
     
     
     
  13.               elements (transposons or "jumping genes") can move within the genome.




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    • The     (Activator) elements contain a              gene similar to that of bacterial            sequences and transposons.






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