Deck 18: Recombinent Dna and Biotechnology

Question 1

Which of the following was used to clean up the oil after the Exxon Valdez spill?

A) Bioremediation
B) Homologous recombination
C) Pharming
D) Microarray technology
E) RNA interference

Answer 1

A

Question 2

Which of the following statements about recombinant DNA is true?

A) All restriction endonucleases generate blunt end frag­ments.
B) Hydrogen bonds between base pairs are very strong.
C) Blunt ends are exposed bases that can hybridize with complementary sequence fragments.
D) Annealing takes place when temperatures are raised.
E) None of the above

Answer 2

E

Question 3

Complementary DNA (cDNA)

A) is produced from ribonucleoside triphosphates.
B) is produced by reverse transcription.
C) is the "other strand" of single-stranded DNA in a virus.
D) requires no template for its synthesis.
E) cannot be placed into a vector because it has the opposite base sequence of the vector DNA.

Answer 3

B

Question 4

Which of the following was an early major use of bacteria for bioremediation?

A) The insertion of transgenes from bacteria that act as toxins against herbivores into plants
B) The use of bacteria to consume contaminating crude oil
C) The production of a pharmaceutical agent in the milk of a transgenic cow
D) All of the above
E) None of the above

Question 5

An expression vector requires all of the following except

A) genes for ribosomal RNA.
B) a reporter gene.
C) a promoter of transcription.
D) an origin of DNA replication.
E) restriction enzyme recognition sequences.

Question 6

From the list below, select the sequence of steps for inserting a piece of foreign DNA into a plasmid vector, introducing the plasmid into bacteria, and verifying that the plasmid and the foreign gene are present:
(1) Transform host cells.
(2) Select for the lack of plasmid reporter gene 1 function.
(3) Select for the plasmid reporter gene 2 function.
(4) Digest vector and foreign DNA with a restriction enzyme, which inactivates plasmid reporter gene 1.
(5) Ligate the digested plasmid together with the foreign DNA.

A) 4, 5, 1, 3, 2
B) 4, 5, 1, 2, 3
C) 1, 3, 4, 2, 5
D) 3, 2, 1, 4, 5
E) 1, 3, 2, 5, 4

Question 7

Which of the following enzymes would be used to join two DNA fragments?

A) Reverse transcriptase
B) DNA polymerase
C) DNA recombinase
D) DNA endonuclease
E) DNA ligase

Question 8

Which of the following could not be used to test whether expression of a particular gene is necessary for a particular biological function?

A) RNAi
B) Knockout technology
C) Antisense
D) Mutant tRNA
E) Transposon mutagenesis

Question 9

RNA interference (RNAi) inhibits

A) DNA replication.
B) neither transcription nor translation of specific genes.
C) recognition of the promoter by RNA polymerase.
D) transcription of all genes.
E) translation of specific mRNAs.

Question 10

The joining of DNAs from two or more genetic sources DNA is called

A) PCR.
B) recombinant DNA.
C) complementary DNA.
D) DNA fingerprinting.
E) None of the above

Question 11

Restriction enzymes

A) play no role in bacteria.
B) cleave DNA at highly specific recognition sequences.
C) are inserted into bacteria by bacteriophage.
D) are made only by eukaryotic cells.
E) add methyl groups to specific DNA sequences.

Question 12

In a genomic library of frog DNA in E. coli bacteria,

A) all bacterial cells have the same sequences of frog DNA.
B) all bacterial cells have different sequences of frog DNA.
C) each bacterial cell has a random fragment of frog DNA.
D) each bacterial cell has many fragments of frog DNA.
E) the frog DNA is transcribed into mRNA in the bacterial cells.

Question 13

Which of the following DNA sequences would most likely be recognized by a restriction enzyme?

A) AGTCGA
B) GTCTGA
C) TAAGGT
D) TAGCTA
E) TCGTGGA

Question 14

Which of the following is used as a reporter gene in recombinant DNA work with bacteria as host cells?

A) rRNA
B) Green fluorescent protein
C) Antibiotic sensitivity
D) Ability to make ornithine
E) Vitamin synthesis

Question 15

"Pharming" is a term that describes

A) the use of animals in transgenic research.
B) plants making genetically altered foods.
C) synthesis of recombinant drugs by bacteria.
D) large-scale production of cloned animals.
E) synthesis of a drug by a transgenic plant or animal.

Question 16

EcoRI makes staggered cuts when it cleaves DNA, creating single-stranded tails called "sticky ends." These ends can form a complementary base pair. In order for this to happen, which of the following conditions is necessary?

A) The presence of specific helicases
B) High enough temperatures
C) Methyl groups at each end
D) Sufficiently low temperature
E) None of the above

Question 17

Possession of which feature is not desirable in a vector for gene cloning?

A) An origin of DNA replication
B) Genetic markers for the presence of the vector
C) Many recognition sequences for the restriction enzyme to be used
D) One recognition sequence each for one or more different restriction enzymes
E) Genes other than the target for transfection

Question 18

The two enzymes that are most important in the construction of recombinant DNA are _______ and _______.

A) restriction enzymes; reverse transcriptase
B) restriction enzymes; DNA ligase
C) reverse transcriptase; DNA polymerase
D) TPA; reverse transcriptase
E) cytochrome oxidase; DNA polymerase

Question 19

Suppose a DNA fragment from a human gene has been cut such that it has sticky ends. A DNA fragment from bacteria with sticky ends complementary to those of the human DNA is added to the mix. What would prevent the complementary ends of the human DNA from rejoining, and thus preventing the formation of a recombinant DNA molecule?

A) DNA ligase
B) Restriction endonuclease EcoRI
C) Reverse transcriptase
D) A cloning vector
E) Nothing

Question 20

The production of many copies of a particular gene is called

A) transfection.
B) restriction.
C) cloning.
D) annealing.
E) inducing.

Question 21

A biologist would most likely use the technique of electroporation to

A) separate proteins based on size and charge.
B) knock out a gene.
C) create antisense DNA.
D) measure expression levels of a gene.
E) coax DNA into host cells.

Question 22

Which of the following statements about the relationship between selectable marker genes and reporter genes is correct?

A) All reporter genes are selectable marker genes.
B) All selectable marker genes are reporter genes.
C) A selectable marker gene cannot be a reporter gene.
D) Both a and b
E) None of the above

Question 23

The disease called crown gall is caused by the

A) insertion of a transposable element carried on the Ti plasmid.
B) transcription of the Ti plasmid in the plant cells.
C) transfer of bacterial genomes into the plant cell genome.
D) rampant multiplication of A. tumefaciens bacteria within the plant.
E) None of the above

Question 24

Which of the following characteristics would not be useful in a vector?

A) A recognition sequence for a restriction enzyme
B) Large size relative to the host chromosomes
C) The ability to replicate independently inside the host cell
D) A reporter gene
E) An origin of replication

Question 25

Use the following to answer questions:
A plasmid has genes that confer resistance to both ampicillin and tetracycline. Foreign DNA is inserted at a restriction enzyme recognition site that lies within the ampicillin gene.
After host cells have been given the opportunity to take up the plasmid, which of the following types of cells should be the most rare?

A) Bacteria with no plasmid and no foreign DNA
B) Bacteria with the foreign DNA, but no plasmid
C) Bacteria with the recombinant plasmid
D) Bacteria with the nonrecombinant plasmid
E) All types should appear with approximately the same frequency.

Question 26

What is the major difference between using green fluorescent protein versus using an antibiotic resistance gene as a reporter gene?

A) The green fluorescent protein can be used only when the host cell is a plant cell because it relies on the process of photosynthesis.
B) The antibiotic resistance gene can be used only when the host cell is an animal.
C) The green fluorescent protein can be used only in transfection, not in transformation.
D) With the green fluorescent protein, no cells are killed in the selection process.
E) Homologous recombination will work only with the green fluorescent protein.

Question 27

Use the following to answer questions:
A plasmid has genes that confer resistance to both ampicillin and tetracycline. Foreign DNA is inserted at a restriction enzyme recognition site that lies within the ampicillin gene.
A cell transformed with the resulting recombinant plasmid should be _______ to ampicillin and _______ to tetracycline.

A) resistant; resistant
B) resistant; sensitive
C) resistant; complementary
D) sensitive; resistant
E) sensitive; complementary

Question 28

Which of the following characteristics makes plasmids useful as a vector?

A) Unlike viruses, plasmids do not need to be coaxed to infect cells by artificial means.
B) Many plasmids contain genes that convey antibiotic resistance.
C) Plasmids can accommodate a large amount (over 100 kb) of DNA.
D) Plasmids use the same origin of replication as eukaryotic cells.
E) All of the above

Question 29

Bacteria are not particularly useful as hosts in studies of eukaryotic gene expression because they

A) are haploid.
B) lack the splicing machinery needed to remove introns from eukaryotic mRNA.
C) have a small genome size.
D) contain plasmids.
E) lack genetic markers.

Question 30

Transgenic cells are created via the _______ of recombinant DNA into cells.

A) recombination
B) transfection
C) ligation
D) restriction
E) complementation

Question 31

Which property of yeast cells makes them useful eukaryotic hosts for recombinant DNA studies?

A) Their rapid rate of cell division
B) Their small genome size
C) Their ease of growth in the laboratory
D) All of the above
E) None of the above

Question 32

Recombinant DNA technology requires not only getting the DNA into the cell, but also getting it to replicate appropriately. In this process, the specificity of which of the following enzymes can present a challenge?

A) DNA ligase
B) DNA polymerase
C) RNA polymerase
D) Reverse transcriptase
E) Replicase

Question 33

In the construction of a transgenic cell, a gene that enables growth on arabinose is added to the vector. This gene is being used as a

A) transformation agent.
B) selectable marker.
C) replicon.
D) cloning vector.
E) expression vector.

Question 34

A researcher inserts a DNA segment at the BamHI recognition site within a plasmid; this site is located within the tetracycline resistance gene. This plasmid also has a gene for ampicillin resistance. Following DNA transformation, the researcher must differentiate the bacteria that have taken up the recombinant DNA from those that have taken up either the DNA segment only or intact plasmids. In doing so, the researcher should select the bacteria that

A) will grow on ampicillin but are sensitive to tetracycline.
B) are sensitive to both antibiotics.
C) are resistant to both antibiotics.
D) will grow on tetracycline but are sensitive to ampicillin.
E) grow only on an enriched medium.

Question 35

Why are plant cells, as opposed to animal cells, particularly useful as hosts for recombinant DNA?

A) Animal cells cannot be cultured
B) Plant cells lack introns.
C) Plant cells have more of a capacity to make totipotent stem cells.
D) Plant cells have reverse transcriptase.
E) None of the above

Question 36

An important vector for the manipulation of plant genes comes from the bacterium A. tumefaciens and is called

A) an EcoRI plasmid.
B) $\lambda$ bacteriophage.
C) BamHI.
D) a Ti plasmid.
E) None of the above

Question 37

A plasmid library and a phage library are constructed from the same genetic material. Which of the following statements is true?

A) The phage library has more clones than the plasmid library because each phage clone contains less DNA.
B) The phage library has fewer clones than the plasmid library because each phage clone contains more DNA.
C) The phage library has fewer clones than the plasmid library because phage libraries do not include nontranscribed DNA.
D) The plasmid library has fewer clones than the phage library because plasmid libraries do not include nontranscribed DNA.
E) The phage library has fewer clones than the plasmid library because phage libraries do not include nontranslated DNA.

Question 38

The DNA from the genome of an organism is chopped into numerous fragments, which then are inserted into vectors that are taken up by host cells. The genetic information that is present in the resulting colonies is called a genomic

A) collection.
B) library.
C) museum.
D) bank.
E) farm.

Question 39

What was the original source of the green fluorescent protein?

A) Green algae
B) Arabidopsis thalania
C) Yeast
D) A firefly
E) A jellyfish

Question 40

The process of inserting recombinant DNA is considered transfection when

A) the host cells are yeast cells.
B) the host cells are E. coli cells.
C) the host cells are mouse tissue culture cells.
D) the vector lacks a replicon.
E) a selectable marker is used.

Question 41

Why is the use of RNAi as a means for blocking RNA translation preferred over the use of antisense RNA?

A) RNAi can be used with DNA chips.
B) Only RNAi can be used to test cause-and-effect relationships.
C) RNAi is more stable than antisense RNA.
D) RNAi is single-stranded and thus easier to produce.
E) None of the above

Question 42

For which of the following processes would we use homologous recombination?

A) Separating DNA fragments by size
B) Inactivating specific genes
C) Examining patterns of expression of genes in different tissues
D) Identifying specific individuals through their genetic differences
E) Producing sticky ends

Question 43

The use of which of the following allows researchers to examine the patterns of gene expression for a large number of genes simultaneously?

A) Antisense RNA
B) RNAi
C) DNA microarray
D) PCR
E) Homologous recombination

Question 44

Which of the following best describes the major advantage of using microarrays to detect gene expression differences across the genome, as compared with hybridization technologies?

A) Microarrays are much faster.
B) Microarrays do not require reverse transcription in order to detect gene expression.
C) Microarrays do not require the production of synthetic oligonuclotides.
D) Both a and b
E) Both b and c

Question 45

Variation at a specific gene is known to affect metabolism in mice, but it is not clear which of the nucleotides are responsible for the changes. In addition to recombinant DNA technology, which the following techniques would be most relevant for revealing which of the nucleotides affect metabolism?

A) Homologous recombination
B) Antisense RNA
C) RNAi
D) Artificial synthesis
E) Mutagenesis

Question 46

Who discovered that a mold makes the antibiotic penicillin?

A) Laura van 't Veer
B) Alexander Fleming
C) Louis Pasteur
D) Francis Crick
E) Leroy Hood

Question 47

Which of the following statements about RNAi technology is false?

A) It is based on a natural process for inhibiting translation.
B) It was discovered only recently (in the 1990s).
C) It has been used as a therapy for macular degeneration.
D) It involves doubled-stranded RNA.
E) All of the above are true; none is false.

Question 48

Laura van 't Veer and her colleagues discovered specific differences between cancer patients with good prognoses and those with poor prognoses. The technique most closely associated with the diagnostic tool they invented is

A) DNA fingerprinting.
B) pharming.
C) RNAi.
D) DNA microarrray.
E) mutagenesis.

Question 49

Methods developed by the _______ industry were most directly responsible for the development of DNA microarray technologies.

A) telecommunications
B) synthetic polymer
C) aerospace
D) semiconductor
E) automobile

Question 50

For which of the following techniques is the synthesis of oligonucleotides most directly useful?

A) Homologous recombination
B) Transformation
C) The polymerase chain reaction
D) Electroporation
E) Electrophoresis

Question 51

Which of the following necessarily makes use of reverse transcriptase?

A) Southern blotting
B) Construction of a gene library
C) Construction of a cDNA library
D) Gene knockout studies
E) Pharming

Question 52

What does the "c" in "cDNA library" stand for?

A) Cytoplasmic
B) Cellular
C) Compatible
D) Chip
E) Complementary

Question 53

Which of the following techniques is most likely to make use of reverse transcriptase?

A) Homologous recombination
B) DNA microarray
C) RNAi
D) Mutagenesis
E) None of the above

Question 54

Which of the following statements about mouse embryonic stem cells is true?

A) They can serve as hosts for transfection studies using homologous recombination.
B) They are unspecialized.
C) They can be used in knockout studies.
D) All of the above
E) None of the above

Question 55

Oblimerson, a drug developed against cancer, is one example of the uses of _______ technology.

A) RNAi
B) homologous recombination
C) microarray
D) antisense RNA
E) bioremediation

Question 56

Which of the following would not be considered a form of biotechnology?

A) Selective breeding to produce cows with greater milk yield
B) Pharming
C) Use of microbes to produce an antibiotic
D) The synthetic production of nylon using organic chemistry techniques
E) All of the above are examples of biotechnology.

Question 57

Which of the following statements is true?

A) A genomic library constructed from human brain tissue will likely be different than a gene library constructed from human pancreatic tissue.
B) A cDNA library constructed from human brain tissue will likely be different than a cDNA library constructed from human pancreatic tissue.
C) A cDNA library would be very useful in examining DNA that does not code for mRNA.
D) Messenger RNAs have a long life span in the cytoplasm.
E) All of the above

Question 58

Which of the following can be used to inhibit translation of a specific gene?

A) Antisense RNA
B) Interference RNA
C) DNA chips
D) Both a and b
E) Both b and c

Question 59

Humans have been using biotechnology for _______ years.

A) less than 50
B) about 100
C) about 200
D) about 1,000
E) at least 8,000

Question 60

The use of which of the following would be most appropriate for inhibiting transcription of a specific gene?

A) Antisense RNA
B) Interference RNA
C) DNA chips
D) Homologous recombination
E) PCR

Question 61

An enhancer would most likely be used for

A) constructing a gene library.
B) constructing an expression vector.
C) performing a restriction digestion.
D) attempting to "silence" a gene.
E) constructing a recombinant plasmid.

Question 62

Pharming is

A) the use of expression vectors to modulate the expression of a gene in a specific tissue.
B) the use of reporter genes.
C) a critical step in the generation of YACs.
D) a type of mutagenesis.
E) None of the above

Question 63

Suppose a strain of corn was genetically engineered to tolerate low pH, and the corn was then planted in a field that is exposed to severe acid rain. This example would be an illustration of

A) the production of a transgenic crop that is adapted to its environment.
B) tailoring the environment to the needs of crop plants.
C) pharming.
D) the complexity of the proteome as compared to the genome.
E) the use of homologous recombination in biotechnology.

Question 64

Which of the following statements about the toxin from B. thuringiensis is false?

A) It was applied as a pesticide long before it was added to plants via recombinant DNA.
B) Many different transgenic crops are grown with the toxin.
C) The use of this toxin has greatly reduced the need to apply pesticides.
D) The toxin acts primarily against vertebrate pests.
E) All of the above are true; none is false.

Question 65

Which of the following is a limitation of conventional breeding, as compared with recombinant DNA technology?

A) The limited range of useful genetic variation
B) The length of time required by the process
C) The lack of precision
D) All of the above
E) None of the above

Question 66

Composting is an example of

A) pharming.
B) bioremediation.
C) biotechnology.
D) Both a and b
E) Both b and c

Question 67

What is glyphosate?

A) An insecticide
B) An herbicide
C) The enzyme that converts plasminogen to plasmin
D) An antisense RNA that binds to bcl2 mRNA
E) A precursor of vitamin A

Question 68

All other things being equal, which of the following genetically altered foods would most likely be of concern regarding human health?

A) Food in which the B. thuringiensis toxin has been added
B) Food that contains an inserted gene that allows plants to grow better in high salt conditions
C) Food that contains an inserted gene that allows plants to grow faster
D) Food that contains an inserted gene that produces $\beta$ -carotene in beans
E) Both a and b

Question 69

What is the major limitation of the dried preparation of the insecticide produced by Bacillus thuringiensis?

A) It has not been approved for use in the United States.
B) It degrades so easily that it has to be applied repeatedly.
C) It is not very toxic.
D) It is new and untested.
E) None of the above

Question 70

Which of the following is an example of an inducible promoter?

A) A promoter that responds only in liver tissue
B) A promoter that responds only when juvenile hormone is present
C) A promoter that responds all the time, regardless of conditions
D) A promoter that possess signal sequences
E) A promoter that produces erythropoietin.

Question 71

In the construction of an expression vector, a signal sequence

A) allows for the expression of a gene in a particular tissue only.
B) allows the expression of a gene to be turned on or off.
C) allows the gene product to be directed to an appropriate location.
D) makes a gene responsive to hormonal stimulation.
E) None of the above

Question 72

Compared with conventional breeding, recombinant DNA technology usually combines _______ genes and takes _______ generations to complete.

A) more; more
B) more; about the same number
C) more; fewer
D) fewer; more
E) fewer; fewer

Question 73

Which of the following is the most likely clinical use of the enzyme TPA (tissue plasminogen activator)?

A) Stopping division of cancer cells
B) Dissolving blood clots
C) Producing insulin
D) Producing antibodies
E) Producing hemoglobin to treat anemia

Question 74

Restriction enzymes recognize and cut at DNA sequences that are _______ (i.e., that read the same way in both directions).

Question 75

A replicon is a segment of DNA that contains _______.

Question 76

Hosts that are altered by the insertion of recombinant DNA are known as _______ organisms.

Question 77

The crew of an eighteenth century ship sailing from Asia has eaten mostly rice during the voyage. Some of the crew members start experiencing vision difficulties and an increased susceptibility to infection. The most likely cause of these symptoms is a deficiency in

A) vitamin B₁₂.
B) vitamin C.
C) $\beta$ -carotene.
D) glyphosate.
E) oblimersen.

Question 78

The primary benefit of using genetic markers in plant breeding is that this technology

A) increases the range of possible new traits that can be introduced into plant breeding.
B) allows one to perform selective inactivation.
C) prevents meiosis.
D) enhances the ability of antisense RNA.
E) enables more precise breeding because specific desirable genetic variants can be identified and selected.

Question 79

The enzyme that catalyzes the joining of DNA fragments is known as _______.

Question 80

Which of the following properties would distinguish an expression vector from typical vectors?

A) Reverse transcriptase
B) A recognition sequence for a restriction enzyme
C) Transcription binding sites
D) A reporter gene
E) The ability to replicate independently within the host