Chapter 14 Study Set

Which of the following events could result in a frameshift mutation? Base deletion Point mutation Incorporation of base analogs Tautomeric shift

Base deletion

Which of the following statements regarding Nucleotide Excision Repair (NER) and Base Excision Repair (BER) is true? Both NER and BER involve the removal of one or more damaged bases by a nuclease. Both NER and BER involve the creation of an apyrimidinic (AP) site. Both NER and BER can be activated by exposure to visible light. Only NER involves the action of DNA ligase to seal nicks in the DNA backbone.

Both NER and BER involve the removal of one or more damaged bases by a nuclease.

Which enzyme is responsible for proofreading during replication?

DNA polymerase

Which repair system uses the RecA and LexA proteins? SOS repair Photoreactivation repair Mismatch repair Proofreading repair

SOS repair

What are the consequences of having pyrimidine dimers in DNA?

These dimers distort the DNA structure and result in errors during DNA replication.

Tautomers of nucleotide bases are isomers that differ from each other in the location of one hydrogen atom in the molecule. T/F?

True

Thymine dimers can be repaired by Photoreactivation Repair or Nucleotide Excision Repair. T/F?

True

Why are X rays more potent mutagens than UV radiation?

X rays are of higher energy and shorter wavelength than UV light. They have greater penetrating ability and can create more disruption of DNA.

Based on the graph, which of the following statements are true? XP individuals almost always develop skin cancer by age 40. At all ages, the non-XP individuals have half the rate of skin cancer as individuals with XP. By age 20, approximately 80% of the XP population has skin cancer. Individuals with XP are more likely to develop skin cancer in their youth than non-XP individuals. For non-XP individuals, the chance of skin cancer increases as they age.

XP individuals almost always develop skin cancer by age 40. By age 20, approximately 80% of the XP population has skin cancer. Individuals with XP are more likely to develop skin cancer in their youth than non-XP individuals. For non-XP individuals, the chance of skin cancer increases as they age.

5' - ACTACGTGA - 3' is a replicated sequence of DNA What mutation would produce: 5' - ACTAAGTGA - 3' 5' - ACTACGTGT - 3'

base substitution mutation

A class of mutations that results in multiple contiguous amino acid changes in proteins is likely to be which of the following? transition transversion recombinant base analog frameshift

frameshift

5' - ACTACGTGA - 3' is a replicated sequence of DNA What mutation would produce: 5' - ACTTACGTGA - 3' 5' - ACTCGTGA - 3'

frameshift mutation

Bacteria can distinguish between a newly replicated DNA strand and the original template strand because the newly replicated strand is methylated, whereas the original template strand is not. T/F?

False

Which nucleotide will base‑pair with the enol form of 5‑bromouracil?

Guanine

A point mutation occurs such that a codon is changed from AGA to AGC. Which term describes this mutation? See Section 14.1 (Page 258) .

transversion mutation