Genetics Exam 2

The regulation of protein function, not gene expression is called ______ regulation. A. posttranslational B. transcriptional C. translational D. posttranscriptional

A. posttranslational

The results of the replica plating experiments by the Lederbergs supported which of the following theories? A. random mutation theory B. physiological adaptation theory C. both theories D. neither theory

A. random mutation theory

What can the Holliday model help explain? A. recombination between homologous chromosomes B. recombination between sister chromatids C. the creation of harlequin chromosomes D. the action of transposons

A. recombination between homologous chromosomes

What is the origin of restriction endonucleases? A. They are part of DNA repair mechanisms in eukaryotic cells. B. They are a defense mechanism against viruses in bacteria. C. They are replication enzymes of yeast. D. They are transposable elements of Drosophila.

B. They are a defense mechanism against viruses in bacteria.

The lac operon is under what type of control? A. positive control B. negative control C. The gene would be expressed constitutively. D. It depends on what the gene encodes.

B. negative control

Long-terminal repeats are unique to which group of transposons? A. integrase B. simple transposons C. LTR retrotransposons D. non-LTR retrotransposons

C. LTR retrotransposons

In E. coli, which protein(s) are necessary for the cell to recognize double-stranded breaks and conduct recombination during meiosis? A. RecG B. RecA C. RecBCD D. RuvABC

C. RecBCD

Allosteric regulation is accomplished by A. a small molecule that fits into an enzyme's active site. B. a large protein that blocks an enzyme's active site. C. a small molecule that fits into a site on the enzyme that is not the active site. D. a small molecule that covalently modifies a site on the enzyme that is not the active site.

C. a small molecule that fits into a site on the enzyme that is not the active site.

Transposons that use an RNA intermediate for transposition are called _____. A. R elements B. RNAi transposons C. retrotransposons D. reverse transposons

C. retrotransposons

What stem-loop conformations favor attenuation? A. 1-2 B. 1-2 and 2-3 C. 2-3 D. 1-2 and 3-4

D. 1-2 and 3-4

After screening a colony of bacteria for a given gene, you discover 100 mutant colonies out of 3 million total colonies. What is the mutation frequency for this gene in the population? A. 1.0 x 105 B. 1.0 x 10-5 C. 3.0 x 105 D. 3.3 x 10-5

D. 3.3 x 10-5

Which of the following is an example of a palindromic DNA sequence? A. 5' - ATCGAC - 3' 3' - TAGCAG - 5' B. 5' - ATCATC - 3' 3' - ATCATC - 5' C. 5' - GCCGCC - 3' 3' - CGGCGG - 5' D. 5' - CTGCAG - 3' 3' - GACGTC - 5'

D. 5' - CTGCAG - 3' 3' - GACGTC - 5'

Translational regulatory proteins recognize specific areas of what molecule? A. tRNA B. ribosome C. rRNA D. mRNA E. None of the answers are correct.

D. mRNA

What do competent cells do? A. resist transfection by a viral vector B. rejoin DNA strands without the aid of DNA ligase C. utilize transposons as a vector D. take up DNA from the external environment

D. take up DNA from the external environment

Which of the following enzymes is required for a transposon to move? A. promotes strand invasion and formation of the D loop B. jumpase C. splicase D. transposase

D. transposase

Anticipation is associated with which of the following?

TRNE mutations

Which process is used to repair DNA lesions?

Translesion synthesis

A translocation that moves a gene from an area of euchromatin to heterochromatin would typically cause _____ in the expression of the gene.

a reduction

A temporary change in the structure of a nitrogenous base is called ______.

a tautomeric shift

Mutations that change the configuration of a protein at a specific temperature are called ____ mutations.

conditional

Which DNA repair process utilizes MutL, MutH, and MutS proteins in E. coli?

mismatch repair

Which DNA repair process often leads to deletion in chromosome sequence?

nonhomologous end joining (NHEJ)

What process repairs damage from UV radiation?

nucleotide excision repair

Silent mutations are possible due to the degenerate nature of the genetic code.

true

Binding of an miRNA to a target mRNA can result in A. degradation of the target mRNA. B. degradation of the miRNA. C. inhibition of transport of the mRNA from the nucleus to the cytoplasm. D. creation of more miRNAs by the RISC complex.

A. degradation of the target mRNA.

The wild-type eye color of Drosophila is red. A single-base mutation occurs that produces a white eye color. Which of the following is correct regarding this mutation? A. It is an example of a mutation that alters protein function. B. Individuals with white eyes are called reversions. C. It would be an example of a silent mutation. D. All of the answers are correct.

A. It is an example of a mutation that alters protein function.

The complete loss of either a guanine or adenine from DNA is an example of _____. A. depurination B. tautomeric shifts C. deamination D. None of the answers are correct.

A. depurination

Which of the following best describes the function of the RecA protein in E. coli? A. double-stranded break model B. recognizes double-stranded breaks in the DNA C. involved in the initial formation of the Holliday junctions D. resolves Holliday junctions into separate chromosomes

A. double-stranded break model

Which recombination model involves formation of a D-loop? A. double-stranded break model B. Holliday model C. single-stranded break model

A. double-stranded break model

Enzymes involved in metabolism are most likely regulated via _____. A. feedback inhibition B. acetylation C. methylation D. None of the answers are correct.

A. feedback inhibition

Acetylation of histones results in A. formation of an open chromatin structure. B. removal of histones from the histone octomer. C. formation of a closed chromatin structure. D. termination of transcription.

A. formation of an open chromatin structure.

Regulatory transcription factors may influence gene expression in which of the following ways? A. recruiting proteins to the promoter that enhance chromatin compaction B. by directly interacting with TFIII to inhibit its binding to the core promoter C. influencing the ability of the RNA polymerase to perform elongation D. directly recruiting RNA polymerase to the promoter without interacting with any other proteins

A. recruiting proteins to the promoter that enhance chromatin compaction

Site-directed mutagenesis allows researchers to produce a mutation at a ______ within a cloned DNA segment. A. specific site B. random site C. semi-localized site that can later be identified by sequencing

A. specific site

Riboswitches have been shown to have regulation of ______? A. transcription and translation B. only transcription C. only translation D. only RNA splicing

A. transcription and translation

Where is the IRE located in the ferritin gene? A. 5' end of DNA B. 5' end of mRNA C. 3' end of DNA D. 3' end of mRNA

B. 5' end of mRNA

Most trinucleotide repeat expansion repeats involve expansion of which of the following? A. GAA B. CAG C. ATG D. any codon containing three of the same bases

B. CAG

CpG islands are associated with which of the following? A. nucleosome location B. DNA methylation C. steroid hormone activity D. termination of translation

B. DNA methylation

After growing a culture of E. coli bacteria in the presence of the T1 phage, you discover that sub-cultures taken from the original exposure show a tremendous fluctuation in the number of colonies that are resistant to the T1 phage. This fluctuation supports which of the following theories? A. Physiological adaptation theory B. Random mutation theory C. Both theories D. Neither theory

B. Random mutation theory

What general transcription factor is most often affected by regulatory transcription factors? A. TFIIB B. TFIID C. TFIIE D. TFIIF

B. TFIID

What accounts for the majority of recombination events during both DNA repair and meiosis? A. a nick in only one strand of the DNA B. the double-stranded break model C. DNA gap repair synthesis D. heteroduplex formation

B. the double-stranded break model

DNA ligase is needed in a cloning experiment for what reason? A. to proofread the vector for mistakes B. to reestablish the stable sugar-phosphate backbone of the DNA molecule C. to allow the vector to enter into the cell D. as a selectable marker

B. to reestablish the stable sugar-phosphate backbone of the DNA molecule

What would be the result if the U-rich sequence after the fourth stem loop in the trp operon was replaced by a UG-rich sequence? A. Attenuation would occur if tryptophan was high. B. Attenuation would occur if tryptophan is low. C. Attenuation would not occur if tryptophan was high. D. None of the answers are correct.

C. Attenuation would not occur if tryptophan was high.

What would be the result of a mutation in Hsp90 that blocked Hsp90's ability to bind to the glucocorticoid receptor? A. Glucocorticoid receptor could not form a dimer. B. The nuclear localization signal would no longer function. C. Glucocorticoid regulated genes would not be controlled even in the absence of glucocorticoid. D. The hormone would not be able to bind to the glucocorticoid receptor.

C. Glucocorticoid regulated genes would not be controlled even in the absence of glucocorticoid.

The individual who first proposed the existence of transposable elements was ____. A. Sturtevant B. Morgan C. McClintock D. Franklin E. Watson

C. McClintock

Which procedure is used to identify a specific DNA sequence within a mixture of many DNA fragments? A. Western blotting B. Northern blotting C. Southern blotting D. Eastern blotting

C. Southern blotting

What occurs during the annealing stage of a PCR reaction? A. The DNA strands separate B. The DNA polymerase copies the template DNA. C. The primers bind to the template DNA. D. The reaction stops.

C. The primers bind to the template DNA.

If CAP could not bind to its CAP site, then what would be the result? Assume lactose is present in each scenario. A. Transcription would be difficult to repress in the presence of glucose. B. Transcription would be difficult to activate in the presence of glucose. C. Transcription would be difficult to activate in the absence of glucose. D. Transcription would be difficult to repress in the presence of glucose.

C. Transcription would be difficult to activate in the absence of glucose.

cDNA is made using what as the starting material? A. plasmid vectors B. viral DNA C. chromosomal DNA D. RNA

D. RNA

Why do yeast genes with a single intron have essentially no alternative splicing? A. Yeast genes never have alternative splicing. B. Removal of a single intron leads to splicing of the poly-A tail which prevents further splicing. C. Methylation of the single intron prevents further splicing. D. Removal of a single intron only leads to one possible outcome for spliced mRNA.

D. Removal of a single intron only leads to one possible outcome for spliced mRNA.

Which of the following mRNAs would be degraded the most rapidly? A. an mRNA with 200 adenine residues at its 3' end B. an mRNA with multiple AAUUU sequences in its 3' untranslated region and with 200 adenine residues at its 3' end C. an mRNA with 100 adenine residues at its 3' end D. an mRNA with multiple AAUUU sequences in its 3' untranslated region and with 10 adenine residues at its 3' end

D. an mRNA with multiple AAUUU sequences in its 3' untranslated region and with 10 adenine residues at its 3' end

Mutations that change the configuration of a protein at a specific temperature are called ____ mutations. A. neutral B. beneficial C. deleterious D. conditional

D. conditional

The presence of a specific plasmid in a bacterial cell is most easily determined by ______. A. its size B. its origin of replication C. its restriction sites D. its selectable marker

D. its selectable marker

Combinatorial factors include activators and repressors as well as A. small effector molecules, proteins that alter the composition of nucleosomes, and DNA methylation. B. small effector molecules, proteins that alter the composition of nucleosomes, DNA methylation, and basal transcription factors. C. small effector molecules, proteins that alter the composition of nucleosomes, but not DNA methylation. D. proteins that alter the composition of nucleosomes and DNA methylation, but not small effector molecules.

A. small effector molecules, proteins that alter the composition of nucleosomes, and DNA methylation.

In the following sequence of DNA, the italicized base has been mutated. What type of mutation is this? 5' - G A T C T C C G A A T T - 3' original strand 5' - G A T C T C C C A A T T - 3' mutated strand A. transition B. transversion C. neither

B. transversion

Which repair process uses enzymes called the DNA-N-glycosylases? A. homologous recombination repair B. direct repair C. base excision repair D. mismatch repair E. nucleotide excision repair F. nonhomologous end joining (NHEJ)

C. base excision repair

Which of the following is not associated with positive transcriptional regulation? A. activators B. inducers C. corepressors D. All of the answers are involved in positive regulation.

C. corepressors

Which of the following is technically NOT part of the genetic information of a transposable element? A. insertion elements B. inverted repeats C. direct repeats D. transposase

C. direct repeats

Small circular pieces of bacterial DNA that are used as vectors in cloning experiments are called _____. A. phages B. viruses C. plasmids D. chromosomes

C. plasmids

Translocations and inversions may cause which of the following? A. TRNE B. anticipation C. position effect D. genome mutations

C. position effect