Deck 27: Recombinant Dna: Cloning and Creation of Chimeric Genes

Question 1

Which of the following is NOT a step in the sequence for construction of a chimeric plasmid?

A)annealing the ends of the vector and foreign DNA
B)cutting the source of the foreign DNA with a restriction endonuclease
C)reannealing the ends of the vector back together
D)cutting the vector plasmid with the same restriction endonuclease

Answer 1

C

Question 2

In the Southern hybridization procedure,after electrophoresis the gel is treated with NaOH and then neutralized before blotting.What is the primary function of the alkaline treatment?

A)to cleave the DNA into smaller fragments to permit greater efficiency of transfer
B)to inactivate any restriction endonucleases that may be in the gel
C)to denature the duplex DNA to single-stranded DNA (ssDNA)
D)to neutralize any acidic phosphate groups that might prevent hybridization

Answer 2

C

Question 3

What are linkers?

A)short sequences of DNA between the promoter and the gene
B)short synthetic DNA duplexes consisting of a restriction site that is ligated onto DNA
C)enzymes that link cloning sites in a sequence of nucleotides
D)enzymes that incorporate foreign DNA into plasmids

Answer 3

B

Question 4

Which of the following is NOT a useful feature of a plasmid for cloning?

A)expressed sequence tag
B)a cloning site
C)a replicator (origin of replication)
D)a selectable marker

Question 5

Which of the following is NOT correct for cDNA libraries?

A)Reverse transcriptase synthesizes a DNA strand complement of the mRNA templates.
B)mRNA templates are isolated using oligo (dA)-cellulose chromatography.
C)Linkers are added and the cDNA is cloned into suitable vectors.
D)The cDNA are copies from mRNA templates.

Question 6

To express a eukaryotic protein in E.coli,the eukaryotic cDNA must be cloned in an expression vector.What does the expression vector need to contain?

A)promoter and ribosomal-binding site
B)promoter and transition start site
C)ribosomal-binding site and hybridization complex
D)introns and exons

Question 7

Which of the following is a property of shuttle vectors?

A)They contain promoters for the expression of the gene.
B)They have origins of replication for 2 different cell types,usually bacteria and yeast.
C)They are capable of incorporating very large DNA fragments.
D)They contain more than 1 antibiotic-resistant gene.

Question 8

How are hybrid proteins or fusion proteins produced?

A)by incubation of 2 proteins with a protease
B)by expression of genes coding for multiple proteins
C)by translation of mRNAs without removing exons
D)by translation of recombinant sequences from expression vectors carrying cDNA inserts cloned directly into the coding sequence of a vector-born protein-coding gene

Question 9

Which vector would be most useful if DNA fragments of about 4 kb are to be cloned?

A)plasmid
B)cosmid
C)YACs (yeast artificial chromosomes)
D)bacteriophage lambda

Question 10

Which of the following is NOT a characteristic of plasmids?

A)They are naturally occurring,circular extrachromosomal DNA.
B)They are able to perpetuate themselves without a host organism.
C)Artificial plasmids can be constructed by restriction endonuclease digestion,insertion,and ligation.
D)An origin of replication must be included in the plasmid to facilitate propagation.

Question 11

Which of the following is NOT required to perform in vitro cloning to produce a library of eukaryotic genomic DNA?

A)DNA ligase
B)a vector such as a plasmid
C)restriction endonuclease
D)mRNA

Question 12

What is a genomic DNA library?

A)a collection of short fragments from nuclear DNA digestion
B)a circular DNA molecule of 1 kb to 200 kb found in bacteria and yeast cells
C)a set of cloned fragments that collectively represent the genes of a particular organism
D)a short segment of DNA whose sequence is complementary to a portion of the DNA of interest

Question 13

What is the term for the study of all the proteins expressed by a certain cell or tissue under specific conditions?

A)genetics
B)proteomics
C)embryogenesis
D)mutagenesis

Question 14

Which of the following is an advantage of using the pET plasmid?

A)The genes to be expressed are under the control of a T7 operator.
B)The T7 polymerase is slower than a typical E.coli polymerase.
C)The expressed protein never accounts for more than 5% of the total cell protein.
D)The T7 polymerase is under the control of the lac operon and is thus active only when induced by an agent such as IPTG.

Question 15

Which of the following is NOT a part of the procedure associated with the Southern blotting (hybridization)technique?

A)hybridization with radioactive probe
B)agarose gel electrophoresis and visualize bands
C)transfer (blot)to nitrocellulose filter
D)digestion of DNA with DNA ligase

Question 16

Which procedure looks at all the genes that are activated during a major metabolic shift or during embryogenesis and development of organisms?

A)fractional expression
B)genetic fractionation
C)functional genomics
D)mutagenesis

Question 17

Which of the following is NOT a part of the process associated with colony hybridization experiments?

A)A replica of the bacterial colonies is obtained on an absorbent disc.
B)Autoradiography of the disc reveals probe-complementary DNA.
C)Host bacteria with plasmid are plated and allowed to grow without media for days.
D)The disc is treated with alkali.

Question 18

Which of the following is NOT a characteristic of YACs (yeast artificial chromosomes)?

A)can successfully propagate DNA molecules of 2 megabase pairs in length
B)have been transferred into animals
C)must include a centromere
D)must include primers

Question 19

Which of the following is the best procedure in order to position a gene in an expression vector downstream from a promoter (i.e.,perform directional cloning)?

A)Use a vector with 2 sites for the same restriction endonuclease.
B)Treat the gene with DNase I.
C)Restrict both the gene and the plasmid with 1 restriction endonuclease,and then screen all colonies for those that express the gene.
D)Restrict each end of the DNA fragment (gene)with a different restriction endonuclease,and do likewise for the plasmid.

Question 20

Which of the following is a method used to insert or transform cells with a plasmid?

A)add the DNA to bacterial cells that have been lightly treated with lysozyme to produce "holes" in the cell wall
B)add the DNA to a heated suspension of cells at 42°C
C)treat the bacteria with Ca²⁺,add the DNA,and briefly heat to 42°C
D)incubate the DNA with the cells overnight at 4°C

Question 21

What would be the 9-residue primer used to amplify this sequence?
5'-ATCGACGTTACGCTACATAGCATAAGGCTT-3'

A)5'-TAGCTGCAA-3'
B)5'-AAGCCTTAT-3'
C)5'-UAGCUGCAA-3'
D)5'-AAGCCUUAU-3'

Question 22

How does RT-PCR differ from basic PCR?

A)Reverse temperatures are used for annealing and transcription.
B)Transcription is reversed from 5'- to 3'-ends.
C)Reverse transcriptase is used to synthesize a cDNA strand complementary to an RNA strand.
D)Reverse transcriptase is used to synthesize an RNA strand from the DNA strand.

Question 23

Reporter genes such as those for green fluorescent protein (GFP)are found on many commercial plasmids.What are these genes used for?

A)to determine if the plasmid is in the host
B)to determine if a gene is present in a library
C)to determine if a foreign protein is being expressed on a vector
D)to determine the relative strength of a promoter sequence

Question 24

How does RNA interference function?

A)siRNA binds to genes and prevents transcription.
B)A single strand of the siRNA binds to the gene transcript,preventing translation.
C)The double-stranded siRNA binds to mRNA to prevent ribosomal association.
D)siRNA binds to RNA polymerase,preventing mRNA production.

Question 25

Which of the following steps is NOT involved with each cycle of amplification in PCR?

A)the addition of fresh dNTPs to the reaction mixture
B)annealing of oligodeoxyribonucleotide primers to DNA
C)thermal denaturation of the target duplex DNA
D)reaction with DNA polymerase at approximately 70°C

Question 26

Which of the following is NOT a strategy for human gene therapy?

A)use of transcription factors
B)incorporation into expression vectors
C)transfer into patient cells
D)introduction of transformed stem cells

Question 27

What is the most promising vector for human gene therapy?

A)bacteriophage l
B)E.coli
C)human papilloma virus
D)adenovirus

Question 28

Which of the following is the appropriate source of the DNA polymerase included in the PCR reaction mixture?

A)E.coli
B)bacteriophage T4
C)Thermus aquaticus
D)Drosophila melanogaster

Question 29

Which in vitro process makes it possible to systematically alter the nucleotide sequence of a cloned gene?

A)protein synthesis
B)mRNA synthesis
C)hybridization
D)mutagenesis

Question 30

What is PCR-based mutagenesis used to create?

A)specifically altered proteins
B)generally modified plasmid vectors
C)mutant bacterial strains
D)mutant DNA libraries