Question 1

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

Accepted Answer

A)  It neutralizes any acid soluble impurities in the gel. 
B)  It cleaves the DNA into smaller fragments to permit greater efficiency of transfer. 
C)  It inactivates any restriction endonucleases that may be in the gel. 
D)  It neutralizes any acidic phosphate groups that might prevent hybridization. 
E)  It denatures the duplex DNA to single-stranded DNA (ssDN
A) .

Question 2

In vitro ____ makes it possible to alter the nucleotide sequence of a cloned gene systematically.

Accepted Answer

A)  protein synthesis 
B)  mRNA synthesis 
C)  hybridization 
D)  mutagenesis 
E)  all are true

Question 3

What would be the 9-residue primer used to amplify:
5'-ATCGACGTTACGCTACATAGCATAAGGCTT-3'

Accepted Answer

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

Question 4

All are steps in the sequence for construction of a chimeric plasmid EXCEPT:

Accepted Answer

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. 
E)  none of the above.

Question 5

Define a probe and explain how probes are used in colony hybridization experiments.​

Accepted Answer

The answer of Define a probe and explain how probes...

Question 6

All are features of a plasmid useful for cloning EXCEPT:

Accepted Answer

A)  expressed sequence tag. 
B)  a cloning site. 
C)  a replicator (origin of replication). 
D)  a selectable marker. 
E)  all are features.

Question 7

PCR-based mutagenesis is used to create:

Accepted Answer

A)  mutant strains of an eukaryotic organism. 
B)  generally modified plasmid vectors. 
C)  mutant bacterial strains. 
D)  mutant DNA libraries. 
E)  specifically altered proteins.

Question 8

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

Accepted Answer

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

Question 9

Each cycle of amplification in PCR involves all of the steps EXCEPT:

Accepted Answer

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. 
E)  none of the above.

Question 10

A genomic DNA library is:

Accepted Answer

A)  a collection of short fragments from nuclear DNA digestion. 
B)  arrays of synthetic oligonucleotides used to select for a specific DNA. 
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. 
E)  a circular DNA molecule of 1 kb to 200 kb found in bacteria and yeast cells.

Question 11

All are characteristic of YACs (yeast artificial chromosomes) EXCEPT:

Accepted Answer

A)  YACs can successfully propagate DNA molecules of 2 megabase pairs in length. 
B)  YACs have been transferred into animals. 
C)  YACs must include a centromere. 
D)  YACs must include telomers. 
E)  All are true.

Question 12

A method used to insert or transform cells with a plasmid is to:

Accepted Answer

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. 
E)  mixing plasmids with an extract of broken cells.

Question 13

How does RNA interference function?

Accepted Answer

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 
E)  none of the above

Question 14

Which of the following describes the major utility of a eukaryotic cDNA library if one is trying to express a protein present in a eukaryotic cell?

Accepted Answer

A)  the library represents all genes that were actively expressed at a specific time 
B)  the genes lack introns and thus can be expressed by bacterial expression systems 
C)  cDNA libraries are readily available 
D)  all of the above are correct 
E)  both A and B are correct

Question 15

Explain how the directed evolution of horseradish peroxidase was developed through high-throughput protein screening.​

Accepted Answer

The answer of Explain how the directed evolution of horseradish...

Question 16

To express a eukaryotic protein in E. coli, the eukaryotic cDNA must be cloned in a(n) ____ that contains ____ and ____.

Accepted Answer

A)  expression vector; promoter; ribosomal-binding site 
B)  hybridization complex; promoter; transition start site 
C)  mRNA; ribosomal-binding site; promoter 
D)  mRNA; introns; exons 
E)  none of the above

Question 17

To position a gene in an expression vector downstream from a promoter (i.e., perform directional cloning), it is best to:

Accepted Answer

A)  use the largest plasmid available. 
B)  treat the gene with DNase I. 
C)  restrict both the gene and the plasmid with one 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. 
E)  use a vector with two sites for the same restriction endonuclease.

Exam 12: Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

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

In vitro ____ makes it possible to alter the nucleotide sequence of a cloned gene systematically.

What would be the 9-residue primer used to amplify: 5'-ATCGACGTTACGCTACATAGCATAAGGCTT-3'

All are steps in the sequence for construction of a chimeric plasmid EXCEPT:

Define a probe and explain how probes are used in colony hybridization experiments.

All are features of a plasmid useful for cloning EXCEPT:

PCR-based mutagenesis is used to create:

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

Each cycle of amplification in PCR involves all of the steps EXCEPT:

A genomic DNA library is:

All are characteristic of YACs (yeast artificial chromosomes) EXCEPT:

A method used to insert or transform cells with a plasmid is to:

How does RNA interference function?

Which of the following describes the major utility of a eukaryotic cDNA library if one is trying to express a protein present in a eukaryotic cell?

Explain how the directed evolution of horseradish peroxidase was developed through high-throughput protein screening.

To express a eukaryotic protein in E. coli, the eukaryotic cDNA must be cloned in a(n) that contains and .

To position a gene in an expression vector downstream from a promoter (i.e., perform directional cloning) , it is best to:

Exam 12: Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

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

In vitro ____ makes it possible to alter the nucleotide sequence of a cloned gene systematically.

What would be the 9-residue primer used to amplify: 5'-ATCGACGTTACGCTACATAGCATAAGGCTT-3'

All are steps in the sequence for construction of a chimeric plasmid EXCEPT:

Define a probe and explain how probes are used in colony hybridization experiments.​

All are features of a plasmid useful for cloning EXCEPT:

PCR-based mutagenesis is used to create:

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

Each cycle of amplification in PCR involves all of the steps EXCEPT:

A genomic DNA library is:

All are characteristic of YACs (yeast artificial chromosomes) EXCEPT:

A method used to insert or transform cells with a plasmid is to:

How does RNA interference function?

Which of the following describes the major utility of a eukaryotic cDNA library if one is trying to express a protein present in a eukaryotic cell?

Explain how the directed evolution of horseradish peroxidase was developed through high-throughput protein screening.​

To express a eukaryotic protein in E. coli, the eukaryotic cDNA must be cloned in a(n) ____ that contains ____ and ____.

To position a gene in an expression vector downstream from a promoter (i.e., perform directional cloning) , it is best to:

Define a probe and explain how probes are used in colony hybridization experiments.

Explain how the directed evolution of horseradish peroxidase was developed through high-throughput protein screening.

To express a eukaryotic protein in E. coli, the eukaryotic cDNA must be cloned in a(n) that contains and .