Chapter 11 Test Bank

After digesting a DNA sequence, a restriction endonuclease can generate

blunt ends, overhangs, or sticky ends.

What makes eukaryotic transcripts easier to isolate than transcripts in bacteria?

mRNA is polyadenylated in eukaryotes.

A shuttle vector is most useful for

making a foreign protein in a mammalian cell.

A(n) ________ gene is a gene that encodes a protein that is easy to detect and assay.

reporter

Which of those below is NOT an important consideration when designing a fusion protein construct?

Avoid hybridization of the fusion gene in the artificial construct.

Which of the following sequences would be cleaved by a type II restriction endonuclease?

D) GAATTC CTTAAG

Which of the following terms is used to describe a synthetic DNA fragment?

DNA cassette

The enzyme that covalently links both strands of a vector and inserted DNA in molecular cloning is

DNA ligase.

Which objective would be best to use a Southern blot rather than a Northern blot?

Determine if a gene is present in a genome.

Engineering a metabolic pathway enables a researcher to use different genes from unrelated organisms.

F

Genomic libraries enable the discovery of individual gene(s) involved in a particular function of interest with cloning vectors in an expression host, such as Escherichia coli.

F

Green fluorescent protein (GFP) is used for detecting translational activity of a fused protein, whereas lacZ reporters are used to detect transcriptional activity of a fused gene.

F

High expression levels of a eukaryotic gene in a bacterium such as Escherichia coli cannot be accomplished due to the presence of introns.

F

One problem with both BACs and YACs is that genetic regions of these chromosomes cannot be subcloned.

F

The lacZ gene is commonly used as a reporter gene, because its substrate lactose is well known and easily measured.

F

Which of the following is NOT a common step in creating a genomic library?

Hybridize DNA sequences to form inserts of a target size range.

Some proteins overexpressed at high levels resulting in the formation of inclusion bodies can abolish the goal of producing large quantities of active protein. What could be done to minimize this issue?

Simultaneously produce intracellular chaperonins.

Although various codons often code for the same amino acid, it is important to choose the codon preferred by the expression host itself.

T

Artificially synthesizing DNA strands (e.g., oligonucleotide primers) involves the careful attachment of one nucleotide at a time to an immobilized sequence.

T

DNA ligase mediates the insertion of foreign DNA into a vector, but it will only be able to do so if the inserts and vector have matching sticky or blunt ends.

T

DNA polymerases from Escherichia coli cannot be used to artificially copy gene sequences with a thermocycler.

T

Developing vaccines for humans relies heavily on manipulating and engineering vectors.

T

Due to well developed molecular tools and careful screening designs, functional genes can be isolated directly by isolation from the environment rather than cultivating the diverse species in a microbial community.

T

If vaccinia viruses were not both immunogenic and relatively benign, they would likely not be a favored vehicle for vaccinations.

T

In principle, a type II restriction endonuclease with an 8-nucleotide recognition sequence should cut 1 in every 48 nucleotide positions.

T

Modification enzymes typically methylate specific bases within the recognition sequence to prevent digestion of the nucleotide sequence by restriction endonucleases.

T

One fundamental technique of genetic engineering includes the ability to cut DNA into random fragments.

T

One important advantage of eukaryotic cells as hosts for cloning vectors is that they already possess the complex RNA and posttranslational processing systems required for the production of eukaryotic proteins.

T

One method to circumvent issues with introns when expression eukaryotic gene is a bacterium is to simply clone the mature transcript.

T

Regardless of the DNA polymerase used in PCR, such as Taq or Pfu, they all have an inherent inability to perfectly copy the template strand, which means the polymerases themselves occasionally make mutations in the sequences they copy.

T

Strong promoters used for genetic manipulation are usually regulated by specific molecules.

T

The key steps in cloning a foreign gene into a vector, regardless of the application, involve isolating the insert fragment, ligating the insert into a vector, and transforming it into a host.

T

While other types exist, Type II restriction endonucleases are by far the most commonly used enzymes for genetic engineering.

T

Which statement is TRUE?

YACs are more likely than BACs to undergo recombination and rearrangement.

The principle behind a nucleic acid probe design is that the probe itself must contain

a key complementary part of the target gene sequence of interest.

Inserting a kanamycin resistance cassette into a catabolic operon to confirm the gene is essential in degradation of a particular compound would involve all of the following EXCEPT

a reporter gene.

To verify a gene was cloned into a vector successfully, sequencing the vector as well as ________ are commonly performed.

agarose gel electrophoresis

To discover a catabolic gene cluster, cloning large sequences of approximately 40 kbp requires the utility of

cosmids or fosmids.

Which of the following is NOT an example of synthetic biology?

developing a novel polyvalent vaccine

At which time period(s) during PCR thermocycling is/are hottest in temperature?

during DNA denaturation

What molecular mechanism/feature does site-directed mutagenesis exploit to introduce a mutation at a specific site?

flanking complementary bound nucleotides permit non-complementary base pairing

Which of those listed below is LEAST similar in what is measured and concluded?

fluorescence in situ hybridization

A poorly immunogenic vaccine often suggests the foreign proteins were not properly recognized by the immune system due to a lack of ________ necessary, which can also be engineered to occur with additional molecular manipulations.

glycosylation

One of the more formidable obstacles to mammalian gene cloning is the presence of

introns.

If a protein to be overexpressed is toxic to the expression host, it is best to select an expression vector that

is inducible.

Cloning vectors can be distinguished from expression vectors by

lacking a promoter site upstream of the insertion site.

Expression vectors are designed to ensure that ________ can be efficiently ________.

mRNA / transcribed

Polyvalent vaccines using vaccinia virus are highly favored by doctors and physicians but are especially challenging for those who develop them, because

multiple foreign proteins simultaneously synthesized often disrupts each other's activity.

If a foreign gene is cloned into an expression host, it is important that the host itself

not produce the protein being studied.

A polymerase chain reaction (PCR) copies an individual gene segment in vitro with a(n) ________ primer(s).

pair of DNA

The Ti plasmid is best suited for genetically manipulating

plants.

Using a host defective in proteases is likely to be necessary when engineering

production of a small protein.

Which construct would be MOST useful in studying translational control?

protein fusion

To estimate the total concentration of a beneficial bacterial species in yogurt, ________ would provide the quickest results.

qPCR

Type II restriction endonucleases

recognize nucleotide sequences that are palindromic.

The principle underlying how salmon were genetically engineered to grow faster is the

replacement of inducible to constitutive hormone production.

The genes encoding luciferase, green fluorescent protein (GFP), and β-galactosidase are typically used in cloning as

reporter genes.

Detecting a specific protein with an antibody is considered a(n) ________ method.

screening

What type of vector can replicate and be maintained stably in two (or more) unrelated host organisms?

shuttle

Recognizing pathogens that contain multiple unique proteins which enable the human immune system to recognize just one and mount an effective response has opened the door on development of some vaccines only being

subunit vaccines.

Which of the following is NOT a characteristic of a type II restriction endonuclease?

unable to cleave methylated DNA