Question 1

Which of the following statements, if any, is false?

Accepted Answer

A)  The polymerase chain reaction (PCR) is a cell-free method of DNA amplification. 
B)  PCR is usually used to amplify a specific DNA sequence of interest using oligonucleotide primers that bind to closely flanking sequences. 
C)  PCR is superior to cell-based DNA cloning for two major reasons: it is much quicker and it allows much greater DNA amplification. 
D)  PCR requires the use of a heat-stable DNA polymerase to make copies of the template DNA. 
A)  The polymerase chain reaction (PCR) is a cell-free method of DNA amplification. 
B)  PCR is usually used to amplify a specific DNA sequence of interest using oligonucleotide primers that bind to closely flanking sequences. 
C)  PCR is superior to cell-based DNA cloning for two major reasons: it is much quicker and it allows much greater DNA amplification. 
D)  PCR requires the use of a heat-stable DNA polymerase to make copies of the template DNA. C

Question 2

In cell-based DNA cloning two types of enzyme are critical for making recombinant DNA. What are they, and what roles do they carry out?

Accepted Answer

1) A class II restriction endonuclease. Enzymes like this recognize short specific sequences, usually spanning a region of 4-8 nucleotides long, and then cut the DNA on both strands, either within this sequence or in the immediate vicinity. As a result of their sequence specificity, they allow cutting of the DNA at specific sites. The restriction endonuclease that is chosen for use is one that is designed to cut the vector molecule at a unique location to produce defined ends. The DNA to be cloned is often a heterogeneous collection of very large DNA fragments with heterogeneous ends, but by cutting with a specific restriction nuclease the DNA population is reduced to DNA fragments that are both of manageable size and also have homogeneous ends that are compatible with the ends of the cut vector, allowing relatively easy joining of the cut vector to the DNA fragments.
2) A DNA ligase. Needed to covalently join the cut vector molecule to the DNA fragments produced by cutting the DNA sample with a restriction endonuclease.

Question 3

Nucleic acid hybridization assays are normally carried out under relaxed hybridization stringency (to maximize the chances of heteroduplex formation) but afterwards, washes are carried out that can be designed to favor perfectly matched sequences only by changing some parameter. Which, if any, of the following changes would be consistent with that aim?

Accepted Answer

A)  An increase in temperature. 
B)  An increase in salt concentration. 
C)  An increase in the concentration of a polar molecule, such as urea or formamide. 
A)  An increase in temperature. 
B)  An increase in salt concentration. 
C)  An increase in the concentration of a polar molecule, such as urea or formamide. A,C

Question 4

List four parameters that affect the stability of a heteroduplex and describe how they have an effect

Accepted Answer

1) Length of the region of base matching

Question 5

During PCR, each cycle has three defined steps. What are they, and what is involved?

Accepted Answer

1) Denaturation - heating of the DNA to

Question 6

With respect to nucleic acid hybridization, which, if any, of the following statements is false?

Accepted Answer

A)  The strength of base pairing between a probe and a complementary target sequence depends on the number of stable base pairs that are formed. 
B)  Among other parameters, the hybridization stringency depends on the salt concentration and temperature of the hybridization reaction. 
C)  To identify a target sequence that is distantly related to the probe, high stringency hybridization needs to be used. 
D)  Under conditions that favor low hybridization stringency long heteroduplexes with significant base mismatching may be stable. 
A)  The strength of base pairing between a probe and a complementary target sequence depends on the number of stable base pairs that are formed. 
B)  Among other parameters, the hybridization stringency depends on the salt concentration and temperature of the hybridization reaction. 
C)  To identify a target sequence that is distantly related to the probe, high stringency hybridization needs to be used. 
D)  Under conditions that favor low hybridization stringency long heteroduplexes with significant base mismatching may be stable.

Question 7

Fill in the blanks below.
In cell-based DNA cloning a key step is ____ 1____ , the stage when the DNA of interest enters the provided host dells. The ____1______ efficiency is usually very low, but when ____ 1____ occurs just a ___2____ DNA molecule usually enters the cell. As a result, a complex starting DNA population can be fractionated by the cells (which effectively act as sorting offices). A second key step allows identification of ____3_____ cells (in the case of bacteria, the host cells are genetically modified to be sensitive to some ____4____ , and the vector carries a gene conferring ____5____ to the ____4____ ) . Many of the transformed cells contain just the vector DNA instead of the desired ____5____ DNA. To identify a specific ____5____ DNA, a more specific assay is required that often involves ____6_____ using a closely related labelled DNA or RNA ____7____.

Accepted Answer

1. transformation. 
2. single.

Question 8

Outline the different approaches to fractionating DNA using gel electrophoresis.

Accepted Answer

Gel electrophoresis can be used to separ

Question 9

Which of the following statements, if any, is false?

Accepted Answer

A)  Cloning DNA in bacteria typically requires a plasmid or a bacteriophage vector. 
B)  Plasmids and bacteriophages are both small circular double-stranded DNA molecules. 
C)  Plasmids and bacteriophages each contain a replication origin that allows them to replicate independently of the bacterial chromosome. 
D)  To be useful as vectors plasmids and bacteriophages need to be genetically modified. 
A)  Cloning DNA in bacteria typically requires a plasmid or a bacteriophage vector. 
B)  Plasmids and bacteriophages are both small circular double-stranded DNA molecules. 
C)  Plasmids and bacteriophages each contain a replication origin that allows them to replicate independently of the bacterial chromosome. 
D)  To be useful as vectors plasmids and bacteriophages need to be genetically modified.

Question 10

In cell-based DNA cloning using plasmids, it is usual to use a plasmid that will allow maximum amplification (increase in copy number) of a recombinant DNA. Sometimes, however, that is not the aim. Explain why.

Accepted Answer

The replication origins of some plasmids

Question 11

Nucleic acid hybridization assays require one of the interacting nucleic acid populations to be labelled in some way. Why is that required and what does it involve?

Accepted Answer

A hybridization assay involves using two

Question 12

What is the essential difference between the Sanger dideoxynucleotide sequencing method and massively parallel (= next generation) DNA sequencing?

Accepted Answer

The dideoxynucleotide sequencing method

Question 13

What is the distinction, if any, between quantitative PCR and real-time PCR?

Accepted Answer

Quantitative PCR is any variant of PCR t

Question 14

Some restriction endonucleases cut DNA to produce sticky ends. What is meant by "sticky ends", and why are the restriction endonucleases that produce them so valuable for DNA cloning.

Accepted Answer

Some restriction nucleases recognize a s

Question 15

Which of the following statements, if any, is false?

Accepted Answer

A)  Amplifying DNA means making many identical copies of one or more starting DNA sequences. 
B)  The object of DNA cloning is to amplify DNA. 
C)  The object of PCR is to amplify DNA 
D)  The object of DNA sequencing is to amplify DNA 
A)  Amplifying DNA means making many identical copies of one or more starting DNA sequences. 
B)  The object of DNA cloning is to amplify DNA. 
C)  The object of PCR is to amplify DNA 
D)  The object of DNA sequencing is to amplify DNA

Question 16

Most PCR reactions are intended to amplify a specific DNA sequence of interest from within a complex starting DNA, often a genomic DNA sample. In addition to a sample of starting DNA of this type in an appropriate buffer with the correct ions to sustain the reaction, list four additional key requirements of the reaction to be successful.

Accepted Answer

1) A heat-stable DNA polymerase.
2) Olig

Question 17

Fill in the blanks below.
In cell-based DNA cloning, a DNA population of interest (which consists of very long DNA fragments) needs to be cleaved by a  _____ ____2______ into manageably short DNA pieces that can be transported more easily into cells. The resulting DNA fragments are joined by a ___3____ ____4______ to a ____5____ DNA, resulting in the formation of a ____6____ ___3___. The ___5___ carries a replication origin that allows it, and the ____6____ ___3____ , to replicate within a suitable host dell, usually some type of ____7____ or ____8____ cell.

Accepted Answer

1. restriction. 
2. nuclease.

Question 18

Which of the following statements, if any, is false?

Accepted Answer

A)  Amplifying DNA always requires a DNA polymerase. 
B)  Amplifying DNA must be carried out in bacterial or yeast cells. 
C)  DNA cloning in cells involves attaching the DNA to be cloned to a vector DNA to form a recombinant DNA that may be circular or linear. 
D)  Vector molecules in DNA cloning must have a replication origin that confers the ability to replicate extrachromosomally. 
A)  Amplifying DNA always requires a DNA polymerase. 
B)  Amplifying DNA must be carried out in bacterial or yeast cells. 
C)  DNA cloning in cells involves attaching the DNA to be cloned to a vector DNA to form a recombinant DNA that may be circular or linear. 
D)  Vector molecules in DNA cloning must have a replication origin that confers the ability to replicate extrachromosomally.

Question 19

Describe the three recognized phases of a PCR reaction.

Accepted Answer

The first phase is the lag phase where t

Question 20

With respect to nucleic acid hybridization, which, if any, of the following statements is false?

Accepted Answer

A)  The probe is a labeled nucleic acid or oligonucleotide that is expected to hybridize to a target DNA sequence within an unlabelled test nucleic acid population. 
B)  The probe is a known single-stranded nucleic acid or oligonucleotide that is intended to hybridize to complementary target sequences in a poorly understood nucleic acid test sample. 
C)  The object of a hybridization assay is to identify target sequences within a test sample that are related to the probe so that some new information is gained about the target sequences. 
D)  During a hybridization assay, a heteroduplex is formed by un-natural base pairing between complementary probe and target sequences that show a sufficiently high degree of base pairing across part or all of their lengths. 
A)  The probe is a labeled nucleic acid or oligonucleotide that is expected to hybridize to a target DNA sequence within an unlabelled test nucleic acid population. 
B)  The probe is a known single-stranded nucleic acid or oligonucleotide that is intended to hybridize to complementary target sequences in a poorly understood nucleic acid test sample. 
C)  The object of a hybridization assay is to identify target sequences within a test sample that are related to the probe so that some new information is gained about the target sequences. 
D)  During a hybridization assay, a heteroduplex is formed by un-natural base pairing between complementary probe and target sequences that show a sufficiently high degree of base pairing across part or all of their lengths.

Which of the following statements, if any, is false?

In cell-based DNA cloning two types of enzyme are critical for making recombinant DNA. What are they, and what roles do they carry out?

List four parameters that affect the stability of a heteroduplex and describe how they have an effect

During PCR, each cycle has three defined steps. What are they, and what is involved?

With respect to nucleic acid hybridization, which, if any, of the following statements is false?

Outline the different approaches to fractionating DNA using gel electrophoresis.

Which of the following statements, if any, is false?

In cell-based DNA cloning using plasmids, it is usual to use a plasmid that will allow maximum amplification (increase in copy number) of a recombinant DNA. Sometimes, however, that is not the aim. Explain why.

Nucleic acid hybridization assays require one of the interacting nucleic acid populations to be labelled in some way. Why is that required and what does it involve?

What is the essential difference between the Sanger dideoxynucleotide sequencing method and massively parallel (= next generation) DNA sequencing?

What is the distinction, if any, between quantitative PCR and real-time PCR?

Some restriction endonucleases cut DNA to produce sticky ends. What is meant by "sticky ends", and why are the restriction endonucleases that produce them so valuable for DNA cloning.

Which of the following statements, if any, is false?

Which of the following statements, if any, is false?

Describe the three recognized phases of a PCR reaction.

With respect to nucleic acid hybridization, which, if any, of the following statements is false?

Fundamentals of Dna, Chromosomes, and Cells

Fundamentals of Gene Structure, Gene Expression, and Human Genome Organization

Principles of Genetic Variation

Single-Gene Disorders: Inheritance Patterns, Phenotype Variability, and Allele Frequencies

Principles of Gene Regulation and Epigenetics

Genetic Variation Producing Diseasecausing Abnormalities in Dna and Chromosomes

Identifying Disease Genes and Genetic Susceptibility to Complex Disease

Genetic Approaches to Treating Disease

Cancer Genetics and Genomics

Genetic Testing From Genes to Genomes, and the Ethics of Genetic Testing and Therapy

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Exam 3: Principles Underlying Core Dna Technologies

Which of the following statements, if any, is false?

In cell-based DNA cloning two types of enzyme are critical for making recombinant DNA. What are they, and what roles do they carry out?

List four parameters that affect the stability of a heteroduplex and describe how they have an effect

During PCR, each cycle has three defined steps. What are they, and what is involved?

With respect to nucleic acid hybridization, which, if any, of the following statements is false?

Outline the different approaches to fractionating DNA using gel electrophoresis.

Which of the following statements, if any, is false?

In cell-based DNA cloning using plasmids, it is usual to use a plasmid that will allow maximum amplification (increase in copy number) of a recombinant DNA. Sometimes, however, that is not the aim. Explain why.

Nucleic acid hybridization assays require one of the interacting nucleic acid populations to be labelled in some way. Why is that required and what does it involve?

What is the essential difference between the Sanger dideoxynucleotide sequencing method and massively parallel (= next generation) DNA sequencing?

What is the distinction, if any, between quantitative PCR and real-time PCR?

Some restriction endonucleases cut DNA to produce sticky ends. What is meant by "sticky ends", and why are the restriction endonucleases that produce them so valuable for DNA cloning.

Which of the following statements, if any, is false?

Which of the following statements, if any, is false?

Describe the three recognized phases of a PCR reaction.

With respect to nucleic acid hybridization, which, if any, of the following statements is false?

Fundamentals of Dna, Chromosomes, and Cells

Fundamentals of Gene Structure, Gene Expression, and Human Genome Organization

Principles of Genetic Variation

Single-Gene Disorders: Inheritance Patterns, Phenotype Variability, and Allele Frequencies

Principles of Gene Regulation and Epigenetics

Genetic Variation Producing Diseasecausing Abnormalities in Dna and Chromosomes

Identifying Disease Genes and Genetic Susceptibility to Complex Disease

Genetic Approaches to Treating Disease

Cancer Genetics and Genomics

Genetic Testing From Genes to Genomes, and the Ethics of Genetic Testing and Therapy

Filters