Chapter 15

Chromosome translocations can result from which of the following DNA repair mechanisms?

•  

  Mismatch repair

•  

  Homologous recombination repair

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  Non-homologous end joining

•  

  Nucleotide excision repair

Xeroderma pigmentosum (XP) is a genetic disease caused by mutations in the nucleotide excision repair (NER) pathway.  In an experiment, scientists fused somatic cells from different individuals affected with XP.  Which of the following results would indicate that two individuals had a mutation in different genes in the NER pathway?

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  The fused cell was more sensitive to UV light than either individual cell.

•  The fused cell is capable of NER.

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  The fused cell is not capable of NER.

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  The fused cell could not survive.

A wild type ion channel is open when a ligand is bound to the channel and closed when the ligand is absent. A mutant version of the ion channel is always open regardless of whether the ligand is present or absent. The mutation in the gene that codes for the ion channel is:

•  

  a loss-of-function mutation.

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  an intragenic suppressor mutation.

•  

  a gain-of-function mutation.

•  

  a null mutation.

Tags

NGSS.HS-LS3-2

Which of the following base changes in DNA is an example of a transition?

•  

  A to C

•  

  C to A

•  

  A to G

•  

  G to C

Which of the following kinds of mutations is MOST likely to be a loss-of-function mutation?

• frameshift

• missense

•  

  transversion

• transition

Tags

NGSS.HS-LS3-2

_____ mutations produce new activity in a gene product or protein and are usually dominant.

• Forward

• Spontaneous

• induced

• gain-of-funtion

Tags

NGSS.HS-LS3-2

Random mutations that occur from errors in replication, crossing over, or DNA repair are called what?

• Gain-of-funtion

• Spontaneous

• Mutagens

• Transversions

Tags

NGSS.HS-LS3-2

Outside agents that damage DNA are called what?

• carcinogens
• teratogens
• antioxidants
• mutagens

Ultraviolet light causes what type of DNA lesion?

• Single-strand breaks
• Base pair mismatches
• Pyrimidine dimers
• Double-strand breaks

During mismatch repair after replication, how does the cell “know” which DNA strand is new and which is the older template strand?

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  The older template strand has epigenetic modifications and the new strand does not.

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  Only the older template strand has guanine bases

•  

  The older template strand has a greater negative charge the new strand

•  

  Older DNA has more purine bases