Deck 15: Genetic Engineering and Biotechnology

Question 1

DNA libraries can be searched to find genes of interest using

A) a probe.
B) differential hybridisation.
C) a selectable marker.
D) a probe and differential hybridisation.
E) a probe and a selectable marker.

Answer 1

a probe and differential hybridisation.

Question 2

Restriction enzymes must be able to cut double-stranded DNA, therefore recognition sequences must

A) be short.
B) have an even number of bases.
C) be palindromic.
D) produce DNA fragments with blunt ends.
E) None of the answers are correct.

Answer 2

be palindromic.

Question 3

Which statement about recombinant DNA technology is CORRECT?

A) Restriction endonucleases cut DNA at random base sequences.
B) Segments of DNA from one organism can be joined to DNA from another organism.
C) DNA fragments from different sources may be ligated using a restriction endonuclease.
D) It is not possible to join DNA from eukaryotes with DNA from prokaryotes.
E) Recombinant DNA cannot be transcribed so that the product is isolated.

Answer 3

Segments of DNA from one organism can be joined to DNA from another organism.

Question 4

A restriction endonuclease

A) is a sequence of DNA from a plasmid.
B) restricts the action of enzymes in the nucleus.
C) is an enzyme that inhibits the functions of the nucleus.
D) is an enzyme that ligates complementary DNA fragments.
E) is an enzyme that cuts DNA at specific base sequences.

Question 5

Transformation of cells can be accomplished by

A) hybridisation.
B) transposable elements.
C) complementation.
D) repeated replication of a DNA molecule.
E) None of the answers are correct.

Question 6

Restriction enzymes are found naturally in bacterial cells. They are there to

A) destroy foreign DNA entering the bacterial cell.
B) separate the two strands of the bacterial DNA.
C) integrate viral DNA into the genome of bacteria.
D) splice DNA fragments into the plasmid.
E) repair DNA.

Question 7

Ligation refers to the process of

A) making double-stranded DNA from single-stranded DNA.
B) making multiple copies of a DNA sequence.
C) separating fragments of DNA.
D) splicing the unattached ends of DNA fragments together.
E) making a cDNA library.

Question 8

In recombinant DNA technology, the term cloning refers to the process of

A) splitting DNA molecules into two strands.
B) extracting DNA from bacterial cells.
C) separating DNA fragments.
D) ligation of sticky ends of DNA.
E) making many copies of recombinant DNA.

Question 9

Complementary DNA (cDNA) libraries are made

A) because DNA in eukaryotes cannot be cloned.
B) to allow analysis of the coding gene regions.
C) as there are no restriction enzymes for non-coding regions of the genome.
D) by using restriction endonuclease digestion of DNA and then ligation of the fragments into the genome.
E) because they are easier to sequence than genomic DNA libraries.

Question 10

The polymerase chain reaction (PCR) is

A) the process that repeatedly replicates a selected segment of DNA.
B) the process that repeatedly forms a polypeptide chain from a selected segment of DNA.
C) a reaction used to hybridise complementary DNA.
D) the integration of a DNA sequence into the genome.
E) a reaction that forms a DNA molecule from an RNA molecule.

Question 11

Reverse transcriptase is

A) the process that repeatedly replicates a selected segment of DNA.
B) a segment of DNA that will hybridise with a known sequence of bases.
C) an enzyme that forms a cDNA molecule from an mRNA molecule.
D) a process that replicates plasmids.
E) the enzyme that transcribes a DNA sequence into a complementary strand.

Question 12

Bacteria that contain the vector plasmid pBluescript II produce blue colonies if grown in a special medium. If these bacteria contain recombinant DNA, inserted into the LacZ gene of the plasmid, they produce white colonies. This is useful because it

A) provides a way of mapping DNA segments.
B) identifies the plasmid from the bacterial DNA.
C) separates different genome fragments.
D) provides a way of identifying transformed bacteria.
E) identifies transposons integrated into the bacterial genome.

Question 13

'Colony hybridisation' is one of the methods used to

A) select specific genes on DNA fragments from the DNA library.
B) insert donor DNA into a host vector.
C) make multiple copies of a DNA segment.
D) make a cDNA copy that will hybridise to a specific sequence.
E) None of the answers describe colony hybridisation.

Question 14

After radioactive labelling of the 5' end of the clones of a 10-base segment of DNA, they were randomly broken at A, C, G, and T bases. The length of each fragment was determined from an autoradiographed gel. The fragments that broke at A were 3, 5 and 10 bases long, fragments that broke at C were 1, 2 and 7 bases long, at a G were 4 and 6 bases long, and at a T were 8 and 9 bases long. The nucleotide sequence of the original clone must have been

A) 3' -CCAGAGCTTA- 5'.
B) 5' -CCAGAGCTTA- 3'.
C) 5' -CCAGAGCTTA-5'.
D) 3' -AATCATCACA- 5'.
E) 5' GGUCUCGAAU 3'.

Question 15

The polymerase chain reaction (PCR) is initiated by

A) inserting a vector into a specific host.
B) inserting a DNA fragment into a vector.
C) binding a primer at a specific site in the DNA molecule.
D) ligating the DNA sequence into the plasmid.
E) separating the DNA fragments on an electrophoresis gel.

Question 16

A linear piece of DNA is cut with restriction enzymes to give the following fragments of DNA:
HindIII 3.5 kb and 2 kb
EcoRI 1 kb and 4.5 kb
HindIII and EcoRI 1 kb 2.5 kb and 2 kb
Which of the following restriction maps shows the positions of the restriction enzyme cutting sites, and the sizes of the resulting fragments?

A) 1 kb 2.5 kb 2 kb
___|__________|________
EcoRI HindIII
B) 1 kb 2 kb 2.5 kb
___|________|__________
EcoRI HindIII
C) 1 kb 4.5 kb
___|__________________
HindIII
D) 1 kb 2.5 kb 4.5 kb
___|__________|__________________
HindIII EcoRI
E) 1 kb 3.5 kb 2 kb 4.5 kb
___|______|____|______________
EcoR1 HindIII EcoR1 HindIII

Question 17

Which would be the best term to describe the uptake, replication and expression of recombinant DNA?

A) Cloning
B) Priming
C) Transformation
D) Restriction mapping
E) Probing

Question 18

It is NOT necessary for a cloning vector to

A) have any restriction enzyme recognition sites.
B) be benign to the host.
C) have a selectable marker.
D) carry a gene for antibiotic resistance.
E) be able to replicate within the cell.

Question 19

Which of the following could be used as a cloning vector for recombinant DNA?

A) Bacteriophage
B) Plasmid
C) Cosmid
D) Bacteriophage and plasmid
E) Bacteriophage, plasmid and cosmid

Question 20

Bacterial cells are said to be competent when they

A) contain plasmids containing inserted DNA.
B) are able to uptake DNA from the external medium.
C) can grow on minimal medium.
D) grow rapidly when they contain plasmids.
E) contain plasmids with antibiotic resistance.

Question 21

Southern, Northern and Western blots respectively are used to detect specific molecules of

A) mRNA, DNA and protein.
B) protein, mRNA and DNA.
C) DNA, mRNA and protein.
D) protein, DNA and mRNA.
E) cDNA, mRNA and protein.

Question 22

Reverse transcriptase is used

A) to create cDNA libraries.
B) to copy RNA into DNA.
C) by retroviruses in their reproductive cycle.
D) All of the answers are correct.
E) None of the answers are correct.

Question 23

In forensic science, DNA analysis is more useful than protein analysis because

A) DNA is less variable than protein and therefore more reliable.
B) only trace amounts of DNA are needed for accurate analysis.
C) there is usually more DNA than protein found at a crime scene.
D) DNA is more stable than proteins and so is able to be detected after a long time.
E) None of the answers are correct.

Question 24

Fusion of somatic cells to form cell hybrids

A) is useful for mapping genes to chromosomes, as chromosomes are identified as they are lost from the hybrid cell.
B) can only be achieved for cells of closely related organisms (same order).
C) creates stable heterokaryon cells that can be used in analysis of homologous chromosome structure.
D) as chromosomes are identified as they are lost from the hybrid cell.
E) All of the above are correct.

Question 25

In the work done to discover the position and function of the cystic fibrosis (CF) gene, chromosome walking was used to

A) determine which chromosome the CF gene was on.
B) clone segments of DNA on one chromosome closer and closer to the CF gene.
C) identify which chromosome the MET gene was on, as MET and the CF gene are linked.
D) create a DNA probe of the appropriate region of chromosome 7.
E) identify DNA polymorphysims on chromosome 7.

Question 26

Variable numbers of tandem repeats (VNTRs) provide us with genetic fingerprints because

A) they create restriction fragment length polymorphisms (RFLPs) by interrupting restriction enzyme recognition sites.
B) they make Western blot analysis easy, because of the large amount of transcript.
C) the number of repeats can vary significantly and can be identified using Southern blot analysis.
D) differences are easily identified between the two alleles.
E) All of the answers are correct.

Question 27

DNA fingerprinting in forensic science relies on

A) the great variability of DNA in non-coding regions.
B) random fragmentation of DNA by restriction enzymes.
C) being able to amplify small amounts of DNA to produce useful quantities for analysis.
D) the great variability of DNA in non-coding regions and being able to amplify small amounts of DNA to produce useful quantities for analysis.

Question 28

In humans, the cystic fibrosis gene was found to be on chromosome 7 because

A) it was linked to the MET gene known to be on that chromosome.
B) of deletion mapping of that chromosome.
C) it was mapped to this chromosome from family history of inheritance.
D) a probe for the gene attached to that chromosome.
E) it was discovered in a DNA library of that chromosome.

Question 29

Which of the following techniques was NOT used in the search for the human sex determining gene?

A) Examination of a number of humans with abnormal sexual development
B) Colony hybridisation
C) Deletion mapping
D) Cloning
E) Linkage to known genes

Question 30

Expression vectors are particularly useful in the pharmaceutical industry because

A) their efficient promoter regions generate multiple transcripts to produce large quantities of protein product.
B) they only accept very small inserts.
C) they help overcome supply problems that limit the availability of some hormones and enzymes.
D) their efficient promoter regions generate multiple transcripts to produce large quantities of protein product and they only accept very small inserts.
E) their efficient promoter regions generate multiple transcripts to produce large quantities of protein product and they help overcome supply problems that limit the availability of some hormones and enzymes.

Question 31

Stem cells may provide treatments for diseases and injuries because

A) they can be injected into a person to repair tissue.
B) in vitro, they can be made to generate specific cell types required by a patient.
C) the tissues they produce could counteract the effects of some genetic diseases.
D) in vitro, they can be made to generate specific cell types required by a patient and the tissues they produce could counteract the effects of some genetic diseases.
E) they can be injected into a person to repair tissue and the tissues they produce could counteract the effects of some genetic diseases.

Question 32

DNA sequence determination has provided a clear picture of the genome structure and has led to

A) the discovery of introns.
B) identification of transposons.
C) identification of human disease genes.
D) All of the answers are correct.
E) None of the answers apply to outcomes from DNA sequencing as these were known before the technology of sequencing was developed.

Question 33

The process of cloning a gene requires

A) the gene to be cut out of the genome using a restriction endonuclease.
B) DNA ligase to join the gene and the vector by the formation of phosphodiester bonds.
C) a DNA vector and a linear DNA molecule of known sequence, to carry the gene.
D) replication of the transformed bacterial cell to produce many copies of the gene.
E) a bacterial cell to have the vector/gene construct inserted by transformation.

Question 34

To clone a specific DNA fragment, the fragment is ligated into a vector. A vector may have the following attributes, EXCEPT

A) it must be a self replicating DNA.
B) it contains an origin of replication that can use the replication machinery of the host.
C) it will lyse the host to enable the fragment to be released.
D) it may enter the host cell after heat shock treatment.
E) it needs to produce a protein product in the host.

Question 35

Different vectors are used to insert DNA fragments into cells for cloning. Which of the following vector types would be most appropriate to determine the function of a gene of 15 kb?

A) Plasmid
B) Bacteriophage
C) Cosmid
D) YAC (yeast artificial chromosome)
E) BAC (bacterial artificial chromosome)

Question 36

A genomic library is

A) fragments of DNA from the whole genome of an organism.
B) transformed host cells containing DNA fragments of the whole genome of an organism.
C) all the genes expressed in a particular cell which have been cloned into a host.
D) phage containing fragments of DNA from an organism.
E) plasmids with expressed genes ligated into their DNA.

Question 37

Which of the following statements in relation to the use of plasmids in biotechnology is NOT correct?

A) Plasmid DNA is associated with histones.
B) Plasmids can be transformed into a bacterial host.
C) Plasmids are self-replicating once transformed.
D) Plasmid DNA can be quickly and easily purified.
E) Plasmids can promote production of recombinant proteins.

Question 38

A farmer asks you about the use of GM technology in agriculture. Using your knowledge of biotechnology, which of the following statements would you tell the farmer to describe the economic and/or environmental benefits of GM to agriculture?

A) Top-soil erosion has been reduced by 90% by the use of conservation tillage practices with herbicide resistant GM crops.
B) GM crops annually reduce CO₂ emissions by billions of tons.
C) The use of agricultural chemicals has been reduced by hundreds of millions of kilograms since the introduction of GM crops.
D) Both the research and production of all GM organisms in Australia is regulated by an independent government entity (OGTR).
E) All of the statements listed here are correct.

Question 39

Why are some ends of a DNA strand cut by restriction endonucleases called 'sticky ends'?

A) Because the enzyme cuts in the same position on both strands
B) Because of the complementarity of the single strands created by the enzyme
C) 'Sticky ends' is just another term for a 'blunt end'
D) Because such ends always end in a thymine, which readily binds to a complementary base more efficiently than any other nucleotide
E) Because the recognition sequence is palindromic

Question 40

How does Agrobacterium incorporate DNA into a cell?

A) All of the options listed here are incorrect.
B) Via a process known as biolistic bombardment
C) Scientists insert DNA of interest into a plasmid that is then co-transformed into Agrobacterium with the Ti plasmid
D) Agrobacterium transfers DNA directly into a cell's nucleus
E) By attaching the DNA to an inorganic and nonreactive particle such as gold or tungsten which is then injected by Agrobacterium into the target cell

Question 41

A fellow student asks you: 'Why do scientists use the Ti plasmid in Agrobacterium to deliver genes into plants, when Ti is an acronym for "tumour inducing"? Surely we don't want to give plants tumours?' What is your response?

A) Tumours are only dangerous in mammals when they can lead to cancer and death. Lacking a true circulatory system, plants are far less vulnerable to such diseases.
B) Ti plasmids used in genetic engineering do not cause tumours as they have been modified by scientists.
C) Ti actually stands for 'transgenic induction' and the student is getting confused with other transgene delivery methods.
D) Only one species of Agrobacterium can deliver the Ti plasmid that might result in tumours, and scientists use a different species.
E) Scientists have 'disarmed' the Agrobacterium host so that it can't deliver the tumour inducing genes, only the transgenes.

Question 42

Currently, more than 17 million farmers worldwide grow GM crops. What percentage of these farmers are in developing countries, and what are the two most common traits found in such GM crops?

A) 95%; herbicide tolerance, drought resistance
B) 50%; insect resistance, increased nutritional content
C) 73%; disease resistance, delayed senescence
D) 35%; insect resistance, herbicide tolerance
E) 90%; insect resistance, herbicide tolerance

Question 43

You observe a scientist extracting gDNA from an organism. The scientist then states he wants to check this material to determine the expression level of some specific genes in the gDNA he has just extracted and purified. How would you advise this scientist?

A) Because he has extracted gDNA, he should do a Southern blot on his extracted material to detect the genes he is specifically interested in.
B) Because he wants to detect expression levels, he needs to do a northern blot on his extracted material as this is the technique used to semi-quantitatively measure transcript levels.
C) He should do Q-PCR or RT-PCR to produce cDNA that he can then analyse for transcript abundance.
D) If he wants to measure expression levels, he needs to instead extract total mRNA and then do a northern blot.
E) If he wants to measure expression levels, he needs to instead extract total mRNA and then do a Southern blot.

Question 44

You are analysing two individual genomes and want to determine if there are any differences in their respective DNA sequences. You hypothesise that the sequences have only very minor single base pair changes. What method would you use to test this hypothesis and why?

A) Northern blots of restriction endonuclease digests, as single base pair changes would alter the recognition sites of the enzymes, thus producing different banding patterns
B) RFLP or Restriction Fragment Length Polymorphism analysis, as a lack of polymorphisms will indicate there are single base pair differences
C) Southern blots of restriction endonuclease digests, as single base pair changes would alter the recognition sites of the enzymes, thus producing different banding patterns
D) By probing with a radio-labelled probe that is complementary to the polymorphic sequences, as the probe will only bind to tandem repeats
E) Using microsatellite analysis via specific primers designed to anneal either side of the single base pair changes, as this would selectively amplify polymorphic sequences which could then be identified

Question 45

What are the three main steps of PCR, and what is their order in a reaction?

A) Denaturation, extension, polymerisation
B) Annealing, reaction, denaturation
C) Hydrolysis, extension, cleavage
D) Denaturation, annealing, extension
E) Polymerisation, reaction, extension