Question 1

What is the first step in constructing a metagenomic library from RNA?
A) The RNA must be converted to cDNA.
B) The RNA must be amplified through PCR, producing many RNA copies.
C) The RNA must be screened to identify the genes of interest.
D) The RNA must be inserted into plasmid vectors.

Accepted Answer

The first step in constructing a metagenomic library from RNA is to convert the RNA to cDNA. This is accomplished through the use of reverse transcriptase, which synthesizes a single-stranded DNA copy (cDNA) of the RNA template. This cDNA can then be amplified and inserted into plasmid vectors to construct the library. Therefore, choice A is the correct answer. PCR amplification and screening of genes of interest would come later in the library construction process.

Question 2

Which of the following terms is used to describe a synthetic DNA fragment?
A) DNA cassette
B) DNA hybrid
C) recombinant DNA
D) artificial chromosome

Accepted Answer

A DNA cassette is a synthetic DNA fragment that can be used to introduce new genetic information into an organism. It typically contains a promoter, one or more genes of interest, and a terminator.

Question 3

The principle underlying how salmon were genetically engineered to grow faster is the
A) removal of a gene responsible for feeling full after eating.
B) replacement of inducible to constitutive hormone production.
C) resistance to bacterial infections which waste metabolic energy in the salmon to fight off.
D) addition of genes to enhance blood circulation and tissue development.

Accepted Answer

The genetic engineering approach used to make salmon grow faster involves replacing the regulatory sequence of an inducible gene (GH1) with the regulatory sequence of a constitutive gene (Cytomegalovirus promoter), resulting in constant production of a growth hormone critical for growth and development. This manipulation leads to increased growth rate and reduced time to market size. The other choices listed are not directly related to the genetic modification strategy used for faster salmon growth.

Question 4

If a protein that could be toxic to the expression host needs to be expressed in large quantities, then it is best to select an expression vector that
A) is not able to be replicated.
B) is inducible.
C) is attached to a normal cell promoter.
D) allows continual expression of the protein.

Accepted Answer

An inducible expression vector allows for tight control of protein expression in the host cell. This means that the toxic protein can be kept at low levels until induction is necessary, minimizing the potential harm to the host cell. The other options do not provide this level of control and may result in toxicity or decreased cell viability.

Question 5

One challenge in cloning human somatotropin is that
A) it consists of multiple polypeptides, making synthesis complex.
B) its gene cannot be cloned as cDNA.
C) it can only be expressed by eukaryotic cells.
D) it is susceptible to digestion by bacterial proteases because it is a small protein hormone.

Accepted Answer

The answer of One challenge in cloning human somatotropin is...

Question 6

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.
A) complex folding
B) methylation
C) glucosylation
D) glycosylation

Accepted Answer

Glycosylation is the addition of sugars to proteins and is often necessary for proper folding and function of the glycoprotein. If a vaccine is poorly immunogenic, it may suggest that the foreign proteins were not recognized properly by the immune system due to a lack of glycosylation, which can be engineered to occur with additional molecular manipulations.

Question 7

The principle behind nucleic acid probe design is that the probe itself must contain
A) a key complementary part of the target gene sequence of interest.
B) all of the nucleotide sequence of the gene of interest to conclusively identify the gene.
C) an antibody to specifically bind to the gene of interest.
D) at least three separate complementary regions of the gene of interest.

Accepted Answer

The key principle behind nucleic acid probe design is to design a probe containing a complementary part of the target gene sequence of interest. The goal of the probe is to hybridize with the target sequence and provide a specific signal for detection. Therefore, the probe should contain a complementary sequence to the gene of interest, usually ranging from 15-30 nucleotides in length. Option B is not necessary as a partial complementary sequence is sufficient for hybridization. Option C is incorrect as probes do not contain antibodies. Option D is not necessary, as a single complementary region can be sufficient for hybridization.

Question 8

Some proteins expressed at high levels form inclusions that are relatively insoluble. What is the most effective way to facilitate purification of these proteins?
A) Use a reporter gene to locate the inclusion.
B) Decrease the number of insertions in the vector.
C) Produce the protein as a fusion protein.
D) Switch to an expression host with a larger intracellular volume.

Accepted Answer

Producing the protein as a fusion protein with a solubility tag or partner can increase solubility of the protein and facilitate purification.

Question 9

The enzyme that covalently links both strands of a vector and inserted DNA in molecular cloning is
A) DNA ligase.
B) DNA phosphatase.
C) DNA hydrolase.
D) DNA transferase.

Accepted Answer

DNA ligase is the enzyme that catalyzes the formation of phosphodiester bonds between the nucleotides of the vector and inserted DNA, covalently linking them together to form a recombinant DNA molecule. DNA phosphatase, DNA hydrolase, and DNA transferase are not involved in this process.

Question 10

Cloning vectors can be distinguished from expression vectors by
A) carrying ori genes for replication of the cloned sequence.
B) having a multiple cloning site (MCS).
C) having a high copy number per cell.
D) lacking a promoter site upstream of the insertion site.

Accepted Answer

Cloning vectors typically lack a promoter site upstream of the insertion site, while expression vectors have a strong promoter for efficient expression of the cloned gene. The other options - carrying ori genes, having an MCS, and having a high copy number per cell - are common features shared by both cloning and expression vectors.

Question 11

It is possible to rapidly screen for mutations in regulatory genes using
A) gene fusions.
B) defective proteases.
C) microinjection.
D) Southern blotting.

Accepted Answer

Gene fusions allow for rapid screening of mutations in regulatory genes by combining the regulatory gene of interest with a reporter gene, allowing for easy visualization of changes in gene expression. Defective proteases, microinjection, and Southern blotting are not efficient methods for rapid screening of mutations in regulatory genes.

Question 12

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
A) attenuated carrier viruses.
B) monovalent.
C) subunit vaccines.
D) purified protein administered.

Accepted Answer

Pathogens that contain multiple unique proteins require subunit vaccines, where one specific protein is selected and purified for administration to activate the immune system's response. Attenuated carrier viruses and monovalent vaccines may not be effective for such pathogens.

Question 13

Which of those below is NOT an important consideration when designing a fusion protein construct?
A) Avoid hybridization of the fusion gene in the artificial construct.
B) Reading frame is the same for both the fusion gene and reporter gene.
C) Transcriptional start and stop signals are shared.
D) Translational start and stop signals are shared.

Accepted Answer

Avoiding hybridization of the fusion gene in the artificial construct is not an important consideration when designing a fusion protein construct. However, ensuring that the reading frame, transcriptional start and stop signals, and translational start and stop signals are correctly arranged is crucial for the proper expression and function of the fusion protein.

Question 14

Polyvalent vaccines using vaccinia virus are highly favored by doctors and physicians but are especially challenging for those who develop them, because
A) coat proteins form a relatively rigid structure and do not allow much space for additional proteins to be expressed.
B) multiple foreign proteins simultaneously synthesized often disrupts each otherʹs activity.
C) vaccinia and most other viruses engineered for vaccines contain only one restriction site for cloning in their genome.
D) virus genetic manipulation uses transfection, which is an inherently inefficient process.

Accepted Answer

Simultaneous synthesis of multiple foreign proteins can lead to interference and disruption of each other's activity, making development challenging.

Question 15

Using a host defective in proteases is likely to be necessary when
A) engineering a complete metabolic pathway requiring several different enzymes.
B) overproducing proteins.
C) producing a small protein.
D) engineering transgenic animals with immune systems.

Accepted Answer

Producing a small protein in a host defective in proteases is necessary because small proteins are more susceptible to degradation by proteases. Using a host with reduced protease activity can help increase the yield of intact, functional small proteins.

Question 16

The Ti plasmid is best suited for genetically manipulating
A) Agrobacterium spp.
B) fish.
C) plants.
D) viruses.

Accepted Answer

The Ti plasmid is naturally found in Agrobacterium spp. and is used to genetically manipulate plants by transferring genes from the bacterium to the plant. Therefore, the best choice is C – plants. The Ti plasmid is not well-suited for genetically manipulating fish or viruses.

Question 17

Which of the following is NOT an example of synthetic biology?
A) assembling gene sequences together into genome and creating a living organism from it
B) creating a new metabolic pathway that produces a previously unidentified compound
C) developing a novel polyvalent vaccine
D) making Escherichia coli photographic

Accepted Answer

Developing a novel polyvalent vaccine is an example of traditional vaccine development, not synthetic biology. Synthetic biology involves engineering biological systems and organisms to perform specific functions or produce desired products through genetic manipulation and design.

Question 18

Which of the following is NOT a limitation to using auxotrophs to prevent the spread of genetically modified genes to wild populations?
A) Auxotrophs may mutate in ways that allow them to synthesize the limiting nutrient.
B) Auxotrophs self-destruct using self-toxins when this method is applied.
C) Auxotrophs often cross-feed from the metabolites of other organisms in the environment.
D) Back mutation to the wild type may occur.

Accepted Answer

Auxotrophs are organisms that cannot synthesize a particular organic compound required for their growth and need to obtain it from their environment. The concept of self-destruction using self-toxins is not a limitation associated with using auxotrophs to prevent the spread of genetically modified genes; rather, it's a strategy that might be employed in containment but is not inherent to the nature of auxotrophs themselves.

Question 19

Which process results in the production of a hybrid polypeptide?
A) vector fusion
B) operon fusion
C) protein fusion
D) translational fusion

Accepted Answer

Protein fusion involves the joining of two or more genes that originally coded for separate proteins, resulting in a single hybrid polypeptide.

Question 20

After digesting a DNA sequence, a restriction endonuclease can generate
A) blunt ends.
B) overhangs.
C) sticky ends.
D) blunt ends, overhangs, or sticky ends.

Accepted Answer

Depending on the specific restriction endonuclease used, it has the capability to generate blunt ends (no overhangs), overhangs (also known as "sticky ends"), or a combination of both. Therefore, the best choice is D, which encompasses all three possibilities.

Quiz 12: Biotechnology and Synthetic Biology

What is the first step in constructing a metagenomic library from RNA?

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

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

If a protein that could be toxic to the expression host needs to be expressed in large quantities, then it is best to select an expression vector that

One challenge in cloning human somatotropin is that

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.

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

Some proteins expressed at high levels form inclusions that are relatively insoluble. What is the most effective way to facilitate purification of these proteins?

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

Cloning vectors can be distinguished from expression vectors by

It is possible to rapidly screen for mutations in regulatory genes using

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

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

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

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

The Ti plasmid is best suited for genetically manipulating

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

Which of the following is NOT a limitation to using auxotrophs to prevent the spread of genetically modified genes to wild populations?

Which process results in the production of a hybrid polypeptide?

After digesting a DNA sequence, a restriction endonuclease can generate