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BIO311: Molecular Biology

Unit 8: DNA Mutation and Repair   DNA mutation is a permanent change in the DNA sequence.  Such a change may be neutral or good or bad for the cell.  A mutation is neutral if it does not affect the expression or function of any gene product.  Rarely, it is good if it brings advantage for the organism or for the offspring of the organism.  Sometimes it is bad if it is disadvantageous, e.g., if it results in cancer or other disease.  DNA polymerases have proofreading activity and work to keep the DNA unchanged.  There are cellular defense mechanisms in multi-cellular organisms, e.g., programmed cell death, which work toward eliminating mutated cells.  You can learn about programmed cell death in BIO402: Pathobiology or BIO404: Cancer Biology courses in the Biology Program.  In general, mutations may arise from two sources: internal mistakes in gene replication or external mutagens.  

Unit 8 Time Advisory
This unit should take you approximately 5.5 hours to complete.

☐    Subunit 8.1: 1.5 hours

☐    Subunit 8.2: 1.0 hour

☐    Subunit 8.3: 1.5 hours

☐    Subunit 8.4: 1.0 hour

☐    Subunit 8.5: 0.5 hours

Unit8 Learning Outcomes
Upon successful completion of this unit, students will be able to: - Compare and contrast single-base mutations and mutations that affect long(er) DNA sequences. - Compare and contrast sense, missense, and nonsense mutations.  - Describe several mutations that cause human disease. - Compare and contrast DNA damage types - Describe biological repair mechanisms.

8.1 Basic Types of Mutations   - Reading: NIH: Genetics Home Reference: "What Is a Gene Mutation and How Do Mutations Occur?" Reading: NIH: Genetics Home Reference: "What Is a Gene Mutation and How Do Mutations Occur?" (HTML)
 
Instruction:  Please study this page.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Reading: John W. Kimball’s "Mutations" Link:  John W. Kimball’s "Mutations" (HTML)
     
    Instruction:  Please study this page.
     
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8.2 Mutagens   - Reading: NCBI Bookshelf: Brown's "Mutation, Repair and Recombination" Link:  NCBI Bookshelf: Brown's "Mutation, Repair and Recombination" (HTML)
 
Instruction: Please study the "Mutations Are Also Caused by Chemical and Physical Mutagens" section on this page.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

8.3 Mismatch Repair   - Reading: NCBI Bookshelf: Griffiths's "Biological Repair Mechanisms" Link:  NCBI Bookshelf: Griffiths's "Biological Repair Mechanisms" (HTML)
 
Instruction:  Please study the "Mismatch Repair" section on this page.
 
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8.4 Base Excision Repair and Nucleotide Excision Repair   - Reading: NCBI Bookshelf: Cooper's "DNA Repair" Link:  NCBI Bookshelf: Cooper's "DNA Repair" (HTML)
 
Instruction:  Please study the "Direct Reversal of DNA Damage" and "Excision Repair" sections on this page.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

8.5 Recombinational Repair   - Reading: NCBI Bookshelf: Griffiths's "Biological Repair Mechanisms" Link:  NCBI Bookshelf: Griffiths's "Biological Repair Mechanisms" (HTML)
 
Instruction:  Please study the "Recombinational Repair" section on this page.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.