Chapter 19

Most TNRE repeats involve expansion of which codon? a. GAA b. ATG c. CAG d. CCC e. Any codon containing three of the same bases

c. CAG

The conversion of cytosine to uracil in DNA is an example of: a. Deamination b. Depurination c. Demethylation d. Tautomeric shifts

a. Deamination

Spontaneous mutations include: a. Depurination, deamination, errors in DNA replication b. UV light, radiation, errors in replication, deamination c. UV light, radiation, deamination, depurination d. UV light, deamination, depurination, errors in DNA replication

a. Depurination, deamination, errors in DNA replication

Which types of mutations are least likely to be subjected to natural selection? a. Silent b. Insertion c. Missense d. Nonsense

a. Silent

A temporary change in the conformation of a nitrogenous base is called: a. Dupurination b. A tautomeric shift c. Deamination d. None of these answers are correct

b. A tautomeric shift

A mutagen is: a. A depurinated base b. An agent that can alter the structure of DNA and cause mutations c. A deaminated base d. A DNA polymerase without a 5' to 3' exonuclease

b. An agent that can alter the structure of DNA and cause mutations

An example of a suppressor mutation would be: a. An intergenic mutation that activates a transcription factor that increases the expression of a normal protein b. An intragenic mutation that restores the inactive protein's structure c. An intergenic mutation that increases the activity of a protein performing a different function as the mutated protein d. A mutation that suppresses cell growth

b. An intragenic mutation that restores the inactive protein's structure

Mutations that change the configuration of a protein at a specific temperature are called ___ mutations. a. Beneficial b. Neutral c. Conditional d. Deleterious

c. Conditional

Which repair mechanism utilizes MutL, MutH, and MutS proteins in E. coli? a. Nucleotide excision repair b. Direct repair c. Mismatch pair d. Base excision repair e. Nonhomologous end joining (NHEJ)

c. Mismatch pair

How does position effect influence gene expression? a. Translocations always result in a gene being recombined into an area of heterochromatin b. Point mutations in promoters frequently occur by this mechanism c. Since this mechanism relies on recombination it relies on the positioning of one allele so that it is under the control of the other allele. d. Translocations may result in a promoter that is normally used for one gene now controlling an entirely different gene

d. Translocations may result in a promoter that is normally used for one gene now controlling an entirely different gene