chapter 20 pearson
which of the following techniques is widely used in genetics and molecular biology to amplify target DNA sequences present in very small quantities
PCR
which gene-targeting technique aims to render a particular gene of interest nonfunctional by having the gene undergo homologous recombination with a target vector with a mutated copy of the gene?
creating gene knockout organisms
which is most often the first step in characterizing a cloned DNA molecule
restriction mapping
Place the steps for cloning DNA in the proper order: 1. Transform the host cell. 2. Digest insert and vector DNA with the same restriction enzyme. 3. Select host cells that have taken up the recombinant vector. 4. Ligate the insert DNA into a vector.
2, 4 , 1, 3
An oligonucleotide is sequenced using the Sanger method. The synthesized strand (not including the primer) has the sequence 5′-CTAGACATG-3′. What is the sequence of the oligonucleotide under study?
5' CATGTCTAG 3'
The recognition sequence for the restriction enzyme EcoRI is 5′-GAATTC-3′ on one strand. What would be the recognition site on the complementary strand?
5′-GAATTC-3'
Which enzyme can be engineered to create changes in a specific sequence to remove, correct, or replace a defective gene or parts of a gene?
CRISPR nuclease
A common approach for making conditional knockout mice starts by crossing a mouse carrying a targeting vector with loxP sites on either side of the gene of interest and a mouse carrying a gene that encodes which enzyme?
Cre recombinase
When mixed, single-stranded ends of DNA fragments from different sources that are cut with the same restriction enzyme can anneal. Which enzyme is required to form phosphodiester bonds between these fragments?
DNA ligase
select the 5 components of PCR
DNA template, heat stable DNA poly, Mg2+, dNTPs
Which of the following techniques involves hybridizing probe with a fluorescent tag directly to a chromosome or RNA?
FISH
Which of the following is NOT true of next-generation sequencing (NGS) and third-generation sequencing (TGS)?
NGS and TGS methods both use dideoxynucleosides and multiple capillary gels
all of the following are used to make a cDNA library EXCEPT
RNA polymerase
The CRISPR (clustered regularly interspaced palindromic repeats)-Cas9 system that allows for gene editing in eukaryotes does NOT use which of the following?
TaqMam probe
which of the following is NOT an advantage of cDNA library
The number of sequences in a cDNA library is smaller than that in a genomic library; therefore, it is easier to probe for a specific sequence.
which vectors can carry the largest insert
YACs
which of the following is a selectable marker
ampR
All of the following are steps in the process to create a knockout mouse EXCEPT
construction of a vector that contains an unmutated transgene to be inserted into the host-cell genome
Select the two statements that are true of a genomic library.
contains at least one copy of all sequences in genome of interest, constructed using restriction enzymes to cut genomic DNA and ligating fragments into vectors
Which gene-targeting technique aims to render a particular gene of interest nonfunctional by having the gene undergo homologous recombination with a target vector with a mutated copy of the gene?
creating gene knockout organisms
Which gene-targeting technique can be used to demonstrate the result of expressing, often overexpressing, a particular gene of interest?
creating transgenic animals
Select the two approaches that use recombinant DNA technology to directly manipulate genes in vivo in ways that allow scientists to learn more about gene function in living organisms?
creating transgenic animals and creating gene knockout organisms
which type of library should be screened to isolate the promotor of a gene
genomic library
all of the following molecules are required for a PCR reaction EXCEPT
ligase
Select three techniques that are commonly used to study gene expression (mRNA production by cells or tissues).
northern blotting, reverse transcriptase PCR, quantitative real time PCR
A 1.5-kb fragment of DNA is cloned into the EcoRI site of a plasmid vector that is 5.5-kb long. The plasmid vector is then transformed into bacteria. If the plasmid DNA is then extracted from a single bacterial colony and digested with EcoRI, what digestion products will be produced if the plasmid contains the fragment and the fragment itself does not contain any EcoRI sites within its sequence?
one 1.5 kb fragment and one 5.5 kb fragment
The plasmid pUC18 carries a fragment of the lacZ gene that confers upon the appropriate host the ability to convert X-gal from a colorless to a blue-colored compound. A DNA fragment is cloned into this region. What color colonies would a plasmid containing the inserted DNA produce? Assume that the plasmid is transformed into an appropriate host strain and plated on medium containing X-gal
only white colonies will be observed
which of the following INCORRECTLY describes a molecular probe
probes are proteins that will bind to a target sequence in a DNA library
Select the three statements that are true of a complementary DNA (cDNA) library.
represents gene active transcriptionally at the time cells were collected for mRNA isolation construction requires the enzyme reverse transcriptase contains complementary DNA copies, made from mRNAs present in cell population
which of the following is NOT true of restriction enzymes?
restriction enzyme can cleave either one or both strands of DNA within the recognition site
Select the two key tools used to construct and amplify recombinant DNA molecules.
restriction enzymes and cloning vectors
PCR reactions often use which enzyme that was isolated from a bacterium living in hot springs?
taq polymerase
how do dNTPs and ddNTPs differ
the 3' carbon has a hydroxyl group in dNTPs and hydrogen in ddNTPs
Which of the following is NOT a characteristic of restriction enzymes?
they accurately and reproducibly cut proteins into smaller peptides
Which of the following is NOT a key property of most DNA vectors?
they can replicate cloned DNA fragments without a host cell
Which of the following statements about ddNTPs is true?
they have a hydrogen at the 3' carbon of the ribose sugar
what is the function of restriction endonucleases in bacteria
they provide a defense mechanism against infection by viruses
what is the purpose of raising the temp to 90-95 at the beginning of each PCR cycle
to seperate the double stranded DNA
why are filters overlaid with xray film when screening of a cDNA library is performed
to visualize probe hybridization events
A DNA fragment that contains an ampicillin resistance gene is introduced into the lacZ gene of a plasmid. What would be the characteristics of transformed bacteria grown on plates containing ampicillin and X-gal?
white colonies that are resistant to ampicillin
A DNA fragment is introduced into the lacZ gene of a plasmid, which also contains a tetracycline resistance gene. What is the appearance of bacteria transformed with this plasmid if they are spread on plates containing tetracycline and X-gal?
white colonies that are resistant to tetracycline
Some proteins require posttranslational modifications for proper folding and function. Which host cells would be the best choice to carry out the production of a recombinant human protein that required posttranslational modification?
yeast
Which of the following vectors can be used to clone large fragments of DNA and contain telomeres at each end for stability?
yeast artificial chromosomes YACs