Deck 2: Molecular Genetic Techniques

Question 1

Which of the following polymerase chain reaction techniques is widely used to study the amount of a specific mRNA within a cell or tissue?

A)qualitative regional transcribed-PCR
B)quantitative reverse targeted-PCR
C)quantitative reverse transcriptase-PCR
D)qualitative regional transposase-PCR

Answer 1

C

Question 2

The chemical mutagen ethylmethane sulfonate (EMS)was used to treat cells,and after 24 hours of incubation,DNA was isolated from these cells and sent for sequencing.Based on the DNA sequence from untreated cells,those treated with EMS showed several of which of the following conversions?

A)G-C to A-T
B)G-A to C-T
C)G-T to A-C
D)G-G to T-G

Answer 2

A

Question 3

Which of the following series of steps does the polymerase chain reaction follow in order to amplify DNA in a test tube?

A)DNA denaturation,primer elongation,primer annealing
B)primer annealing,DNA ligation,primer elongation
C)primer elongation,primer annealing,DNA ligation
D)DNA denaturation,primer annealing,primer elongation

Answer 3

D

Question 4

A polylinker increases the versatility of a DNA plasmid because it contains:

A)a DNA recognition sequences for several different restriction enzymes.
B)a DNA sequence to allow the vector to replicate.
C)
C)a DNA sequence that confers resistance to ampicillin.
D)b and

Question 5

You want to amplify a region of yeast DNA using PCR so that this fragment can be cloned into a plasmid.Which of the following is needed for the PCR?

A)RNA polymerase
B)DNA ligase
C)DNA helicase
D)Taq polymerase

Question 6

Which of the following enzymes will produce a blunt end (the cut site is indicated by the * in the recognition sequence)?

A)TaqI (T*CGA)
B)EagI (C*GGCCG)
C)EcoRV (GAT*ATC)
D)NsiI (ATGCA*T)

Question 7

Organisms that are considered polyploid have:

A)more than one genome.
B)more than two copies of each chromosome.
C)only one copy of each chromosome.
D)multiple copies of a specific chromosome.

Question 8

One common difference between meiosis and mitosis is that in meiosis,the end result is:

A)four cells each having two chromosomes.
B)two cells each having one chromosome.
C)four cells each having one chromosome.
D)two cells each having two chromosomes.

Question 9

In addition to sequencing,intronic sequences can be identified in a genomic DNA library using which of the following methods?

A)Southern blotting
B)in situ hybridization
C)PCR
D)Southern blotting and PCR

Question 10

Construction of a cDNA library involves several steps,the first usually involves:

A)digesting noncoding regions of DNA.
B)cloning complementary double-strand DNA into a plasmid.
C)isolating total RNA from the organism or cell type of interest.
D)reverse transcribing RNA into cDNA.

Question 11

Which of the following tests is used to determine if different recessive mutations are in the same gene?

A)centimorgan linkage test
B)conditional test
C)cohabitation test
D)complementation test

Question 12

Describe how genetic complementation can be used in yeast to determine whether two different recessive mutations are in the same or different genes.

Question 13

You have an E.coli plasmid containing a mammalian cDNA and want to isolate the cDNA to use in another experiment.The plasmid map reveals that you can isolate the complete cDNA by digesting the plasmid with EcoRI.How many bands would there be after a successful EcoRI restriction enzyme digest?

A)one
B)two
C)three
D)four

Question 14

A mutation in one gene that counteracts the effects of a mutation in another gene is known as a

A)temperature-sensitive mutation.
B)recessive mutation.
C)conditional mutation.
D)suppressor mutation.

Question 15

To see if your polymerase chain reaction was successful and it amplified the right sequence of interest,you electrophorese the products from the reaction on an agarose gel.After staining the gel you find there are two bands of different sizes.Which one of the following is a possible explanation for these results?

A)The PCR induced a frame shift mutation into the DNA sequence.
B)
B)RNA polymerase copied the DNA into two copies of RNA.
C)The primers annealed to two different templates.
D)a and

Question 16

Sequencing methods were used to test the integrity of the cDNA library and when this was done you found many of the sequences were those found in introns.After troubleshooting you determined that the reason these intronic sequences were present was because during the construction of this cDNA library:

A)genomic DNA was present.
B)retroviral DNA was a contaminant.
C)endonucleases should have been added.
D)RNA polymerase was present.

Question 17

Describe the properties and utility of temperature-sensitive mutations.

Question 18

A recombinant DNA vector:

A)cannot replicate in a host.
B)does not contain bacterial DNA sequences.
C)contains DNA sequences from only one source.
D)contains DNA sequences that can be cleaved by restriction enzymes.

Question 19

Crossing of a homozygous wild type with a mutant that is heterozygous for a dominant mutation will result in F₁ progeny of which

A)all show the mutant phenotype.
B)half show the wild-type phenotype and half show the mutant phenotype.
C)three-fourths show the wild-type phenotype and one-fourth show the mutant phenotype.
D)all show the wild-type phenotype.

Question 20

A mutation that changes a cysteine codon to a tryptophan codon is called a

A)missense mutation.
B)nonsense mutation.
C)silent mutation.
D)none of the above.

Question 21

In the large-scale production of a particular human protein in E.coli cells,the cDNA corresponding to the protein was modified so that the expressed protein would have six histidine residues at the C-terminus.The purpose of this modification was to

A)facilitate transfer of the cDNA into the E.coli cells.
B)provide a promoter for the transcription of the cDNA in E.coli.
C)facilitate purification of the expressed protein though binding to an affinity column containing chelated nickel atoms.
D)prevent degradation of the expressed protein by E.coli proteases.

Question 22

A haplotype is a set of closely linked genetic markers on a particular chromosome that tend to be inherited together.The genetic technique that looks at inheritance patterns and uses haplotypes in determining gene locations is:

A)linkage mapping.
B)linkage disequilibrium mapping.
C)candidate gene approach.
D)all of the above

Question 23

Next generation sequencing is much more efficient than the Sanger method because
a.it uses an RNA template instead of DNA.
b.it uses gel electrophoresis to resolve end-labeled strands of DNA.
c.it uses PCR amplification.
d.it uses gel electrophoresis to resolve end-labeled strands of DNA,and it uses PCR amplification.
Ans.c

Question 24

Compare the advantages and limitations of microarrays and Northern blots for analyzing gene expression.

Question 25

Linkage studies can map disease genes with a resolution of about one centimorgan.Typically,the physical distance of a DNA region this size is approximately:

A)7.5 × 10² base pairs
B)7.5 × 10³ base pairs
C)7.5 × 10⁴ base pairs
D)7.5 × 10⁵ base pairs

Question 26

A specific nucleic acid fragment is used in all but one of the following techniques?

A)Southern blotting
B)Western blotting
C)Northern blotting
D)in situ hybridization

Question 27

Which human disease is the result of an inherited X-liked recessive mutation?

A)Tay-Sachs disease
B)Duchenne muscular dystrophy
C)cystic fibrosis
D)none of the above

Question 28

The identification of disease genes can be made more complicated because of

A)genetic heterogeneity.
B)location of the gene on the X chromosome.
C)polygenic traits.
D)genetic heterogeneity and polygenic traits.

Question 29

In situ hybridization is a powerful tool used in gene expression studies because it provides the investigator with information pertaining to

A)the cellular and tissue-specific localization of the mRNA encoded by a particular gene.
B)the activity of the protein translated from a particular mRNA.
C)the size of the mRNA transcript.
D)all of the above

Question 30

DNA ligase

A)synthesizes DNA from an RNA template.
B)forms a phosphodiester bond.
C)joins Okazaki fragments.
D)b and c

Question 31

Modifying the DNA sequence of a gene of interest by appending to it a DNA sequence that encodes a stretch of amino acids recognized by a known monoclonal antibody is called:

A)epitope tagging.
B)in situ hybridization.
C)polymerase chain reaction.
D)next-generation sequencing.

Question 32

Describe the essential features of a yeast shuttle vector.

Question 33

Describe some typical features of a restriction enzyme recognition sequence.

Question 34

Microsatellites,which often vary in DNA sequence between individuals,are also called:

A)single-nucleotide polymorphisms.
B)nucleotide tandem replacements.
C)short tandem repeats.
D)autosomal dominant polymorphism.

Question 35

Which of the following is a functional element of a plasmid?

A)origin of replication
B)drug-resistance gene
C)polylinker sequence
D)all of the above

Question 36

The process by which genes cloned into specialized eukaryotic vectors are introduced into cultured animal cells for transient expression analysis is called:

A)ligation.
B)hybridization.
C)transfection.
D)transformation.

Question 37

What is epitope tagging? What is its application?

Question 38

Which of the following is used to compare gene expression in cells under different conditions?

A)Southern blotting
B)P-element insertion
C)stable transfection
D)microarray analysis

Question 39

Northern blotting is a technique used to detect which one of the following in cells and tissues?

A)DNA.
B)RNA.
C)protein.
D)carbohydrate.

Question 40

You are growing a population of cells that appear to be resistant to G418,a chemical that is normally toxic to cells.Upon further analysis of the cells' genome you find that it contains a genomic sequence that encodes the protein neomycin phosphotransferase.What would you do to test if this protein confers resistance to the G418 chemical?

A)determine if the cells are also making β-galactosidase
B)tag the protein with green fluorescent protein to see if it is degraded by G418
C)label a fragment of the gene to see where it is expressed
D)clone the gene into a G418-sensitive cell line,then treat these cells with G418

Question 41

How does genetic heterogeneity or polygenic traits make the identification of a disease gene more difficult?

Question 42

How can linkage analysis determine the position of genes on a chromosome?

Question 43

In RNA interference studies,the double-stranded RNA

A)disrupts the target DNA sequence.
B)results in the destruction of the target mRNA.
C)destroys the target protein.
D)all of the above

Question 44

CRISPR,one of the latest technologies to allow investigators to edit DNA sequences within a genome,can inactivate gene function if it produces a frameshift mutation leading to which one of the following sequences?

A)TAG
B)TTT
C)TGT
D)TTA

Question 45

How can the function of an essential gene required for embryonic development be studied in an adult knockout mouse?

Question 46

A step in the generation of knockout mutations in mice includes selection of embryonic stem (ES)cells that are

A)resistant to G418 and resistant to ganciclovir.
B)sensitive to G418 and resistant to ganciclovir.
C)resistant to G418 and sensitive to ganciclovir.
D)sensitive to G418 and sensitive to ganciclovir.

Question 47

To study the function of the essential cytosolic Hsc70 genes in yeast,researchers constructed a shuttle vector in which a copy of the Hsc70 gene was ligated to the GAL1 promoter.The vector was then introduced into haploid yeast cells in which all four copies of the Hsc70 genes had been disrupted.Following introduction of the vector,you would expect that

A)the yeast cells would grow on both glucose and galactose media.
B)the yeast cells would grow on glucose but not galactose medium.
C)the yeast cells would grow on galactose but not glucose medium.
D)on transfer to either glucose or galactose medium,the vector-carrying cells would eventually stop growing because of insufficient Hsc70 activity.

Question 48

Although small hairpin RNAs are used in RNAi-mediated destruction of a target mRNA,in order for them to be effective,the double-stranded RNA must be cleaved by which of one of the following?

A)RISC
B)RNA polymerase
C)exonuclease
D)dicer

Question 49

As an investigator you want to functionally inactivate a gene without altering its sequence.Which of the following would you use to accomplish this?

A)gene knockout
B)RNA interference
C)dominant negative mutation
D)RNA interference and dominant negative mutation

Question 50

RNAi is used to functionally inactivate genes in cells and whole organisms like C.elegans.Describe the basics of how you would knock down the expression of a gene required for muscle formation in C.elegans and what method could you use to confirm that your results were specifically attributed to the RNAi?