mastering microbiology chapter 9
any genetically modified bacteria are programmed with a self-destructive gene that will eventually destroy the organism. T/F
true
dna fingerprints are actually
dna fragments
Special considerations must be taken when using bacteria to produce a eukaryotic protein. What is the cause for this additional difficulty? Transcription is in prokaryotes is very different from transcription in eukaryotes. Eukaryotic genes contain introns, which prokaryotic cells cannot remove. Prokaryotic DNA contains different nucleotides. Translation in prokaryotes is very different from translation in eukaryotes
Eukaryotic genes contain introns, which prokaryotic cells cannot remove.
cDNA is made from
an mRNA template
southern blotting is used to
identify particular sequences of dna
A disadvantage of using E. coli to produce recombinant proteins for human pharmaceuticals is the possibility of endotoxin contamination. T/F
true
Which of the following is an example of a cloning vector? plasmid tick human growth hormone mosquito ribosomal RNA
plasmid
Recombinant DNA can be introduced into a host cell by any of the following methods EXCEPT __________. protoplast fusion transformation polymerase chain reaction microinjection electroporation
polymerase chain reaction
Sequencing a genome provides __________. restriction fragments a gene sequence identity of proteins expressed by the cell the order of nucleotides in a genome
the order of nucleotides in a genome
If a recombinant plasmid is put in solution with E. coli, the bacteria may pick up the plasmid by __________.
transformation
The cells are phe- and the media lack phenylalanine. Why are the phe- cells growing on plate C?
transformation
Viral DNA is an important cloning vector because it can typically be combined with relatively large pieces of DNA. T/F
true
An ampicillin-sensitive culture of E. coli is transformed with a plasmid that contains the gene of interest plus an ampicillin-resistant gene. If it is then plated on an ampicillin-containing growth medium, __________. no bacteria will grow only the lactose-positive bacteria will grow only the ampicillin-sensitive bacteria will grow only the bacteria with the plasmid will grow all gram-negative bacteria will grow
only the bacteria with the plasmid will grow
Which of the following might specifically be used as part of a reverse-genetics approach to studying a gene? PCR Ti plasmid reverse transcriptase RNA interference Southern blotting
RNA interface
which of these statements is true for restriction enzymes
Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA.
For which of the following applications can PCR be used? sequencing DNA making copies of a gene to be put into another organism identifying traits that may lead to a genetic disorder all of the above none of the above
all of the above
Which of the following is a safety issue related to the use of recombinant DNA? reduction in populations of "desirable" insects due to the use of Bt insecticide allergic reactions to components in genetically modified foods spread of bioengineered traits, such as herbicide resistance, into related weed species all of these End of Question 20
all of these
If you put the gene for Bt toxin from Bacillus thuringiensis into a tomato plant, the resulting plants will __________. die be toxic to insects that eat them have a Bacillus infection be toxic to humans who eat the tomatoes
be toxic to insects that eat them
What is/are the role(s) of dNTPs in a PCR? They are the monomers for the DNA strand to be synthesized. They provide energy for the DNA polymerization to occur. Both of the above answers apply. Neither of the above answers applies.
both of the above answers apply
Which of the following is not a constituent of PCR? DNA primers dUTP target DNA dATP DNA polymerase End of Question 2
dUTP
In nature, the function of restriction enzymes is to __________.
destroy bacteriophage dna
A plasmid that has been cleaved with EcoRI can recombine with another plasmid that has been __________. digested with EcoRI digested with HindIII amplified by PCR cleaved with BamHI
digested with EcoRI
DNA can be introduced into plant cells only if the cell wall is first removed. T/F
false
If a foreign gene inserted into a plasmid inactivates the beta-galactosidase gene, a bacterium containing that plasmid would form blue colonies on the X-gal medium. T/F
false
For Agrobacterium tumefaciens to be used to introduce foreign DNA into a plant cell, that DNA must first be __________. inserted into the Ti plasmid of A. tumefaciens outside the T-DNA region inserted in an A. tumefaciens plasmid other than the Ti plasmid inserted into the main chromosome of A. tumefaciens isolated from the crown gall using the appropriate restriction enzyme inserted into the T-DNA region of the Ti plasmid of A. tumefaciens
inserted into the T-DNA region of the plasmid of A tumefaciens
why is a tempertautre of 94 required for pcr
it allows the strands of target dna to seperate
In genetic engineering, antibiotic resistance genes are often cloned into a vector to __________.
make direct selection of a clone possible
A good cloning vector __________. should be readily degraded in the host should not be able to be cut by more than one restriction enzyme should not be capable of replication should have a gene or genes that allows for selection of transformed host cells should have a high concentration of guanine
should have a gene or genes that allows for selection of transformed host cells
lasmids that can exist in disparate species such as a bacterium and a plant cell are called __________ vectors, and they can be used to transfer cloned DNA from one type of organism to another.
shuttle
what is the ultimage goal of recombinant dna technology
to improve the organisms
If a foreign gene inserted into a plasmid inactivates the β-galactosidase gene, a bacterium containing that plasmid would form blue colonies on X-gal medium. T/F
true
Place the following steps of PCR in order: Annealing of primers Separation of strands Synthesis of new DNA
2,1,3
Put the following events of PCR in order: Repeat 30+ times. Denature at 94oC. Extend at 72oC. Prime at 60oC.
2,4,1,3
Which of the following statements correctly differentiates biotechnology from rDNA technology? Biotechnology includes genetic modification of eukaryotic cells and prokaryotic cells, whereas rDNA technology exclusively involves the genetic modification of bacteria. Biotechnology is concerned only with the production of recombinant proteins, whereas rDNA technology is concerned exclusively with DNA. Biotechnology includes techniques for gene amplification, whereas rDNA technology includes techniques for altering the nucleotide sequence of an organism's DNA. Biotechnology involves any use of microorganisms or cells to make products, regardless of the means used. Recombinant DNA technology involves methods for handling and modifying DNA and inserting it into different types of cells.
Biotechnology involves any use of microorganisms or cells to make products, regardless of the means used. Recombinant DNA technology involves methods for handling and modifying DNA and inserting it into different types of cells.
The following sequential steps are used to make a recombinant cell. Which of these steps occurs LAST? Isolate gene of interest. Grow cells containing vector with gene. Insert gene into a vector. Vector is taken up by cell.
Grow cells containing vector with gene.
Which of the following statements correctly differentiates a genomic library from a cDNA library? Genomic libraries are prepared from eukaryotes, and cDNA libraries are prepared from prokaryotes. Genomic libraries contain only those genes that a cell is currently expressing, whereas cDNA libraries contain all of the cell's genes, whether expressed or not. A genomic library contains only noncoding DNA sequences, whereas a cDNA library contains only coding sequences. cDNA libraries can be used for sequencing, but they cannot be transcribed and translated. Genomic libraries can be used for sequencing and for production of the desired protein product. A genomic library contains fragments of the entire DNA in an organism's genome. A cDNA library contains the coding sequences of eukaryotic genes (minus the introns).
a genomiv library contains fragments of the entire DNA in an organisms genome. A cDNA library contains the coding sequences of eukaryotic genes minus the introns
Which of the following is NOT a step in Southern blotting? addition of a radioactive probe made from the gene of interest transfer of DNA fragments to filters separation of DNA fragments by gel electrophoresis digestion of sample DNA with restriction enzyme addition of heat-stable DNA polymerase
addition of heat stable polymerase
Which of the following can result once the recombinant DNA molecule has been made? It is inserted into a host cell. It is copied many times inside a host cell. It can be transcribed and then translated into a desired protein. All of the above actions can result. None of the above actions can result. End of Question 4
all of the above can result
Which of the following can be used as vectors to genetically modify cells? plasmids viruses shuttle vectors all of these End of Question 4
all of these
In genetic engineering, antibiotic-resistance genes are usually cloned into vectors to __________. allow selection for bacteria containing the vector select for cells having undergone spontaneous mutation kill the recombinant organisms select for cells that cannot grow
allow selection for bacteria containing the vector
Assume you insert a specific gene into a plasmid and use blue-white screening. You plate the transformed E. coli cells on an ampicillin X-gal medium. Cells that produce blue colonies are __________. ampicillin resistant but do not contain the new gene ampicillin resistant and contain the gene of interest ampicillin sensitive and can hydrolyze X-gal ampicillin sensitive and cannot hydrolyze X-gal
ampicillin resistant but do not contain the new gene
When two DNA pieces cut with the same restriction enzyme are combined, sticky ends will __________. associate by covalent bonds associate because of DNA ligase associate only if they are double-stranded not associate associate by complementary base pairing and hydrogen bonds
associate by complementary base pairing and hydrogen bonds
If DNA ligase were NOT used in the creation of a recombinant plasmid, __________. the bacterium to receive the recombinant plasmid would not be competent and thus would be unable to take up the plasmid base-pairing would occur but the sugar phosphate backbone would not be connected links between adenine and thymine would not occur hydrogen bonds between complementary bases could not form links between guanine and cytosine would not occur
base pairing would occur but the sugar phosphate backbone would not be connected
The use of microorganisms, cells, or cell components to make products such as hormones, antibiotics, food, or vaccines is known as __________.
biotechnology
For the introduction of a genetically modified plasmid into E. coli, __________. protoplast fusion must be used no treatment is needed, because the cells are naturally competent microinjection must be used a gene gun must be used calcium chloride and heat shock can be used
calcium chloride and heat shock can be used
To express a human gene in a bacterium, cDNA must be made because bacteria __________. have reverse transcriptase usually destroy human DNA splice RNA cannot remove introns
cannot remove introns
Recombinant DNA technology is used for all of the following EXCEPT ________. insertion of genes from humans or plants into bacteria or viruses human-insulin production by bacterial cells amplification of DNA for microbe identification hepatitis-B-vaccine production using yeast cells culturing unknown organisms
culturing organisms
Recombinant DNA technology is used for all of the following EXCEPT __________. human-insulin production by bacterial cells insertion of genes from humans or plants into bacteria or viruses culturing unknown organisms amplification of DNA for microbe identification hepatitis-B-vaccine production using yeast cells
culturing unknown organisms
Real-time PCR differs from traditional PCR in that real-time PCR amplification is monitored by gel electrophoresis. T/F
false
Yeasts can only be genetically engineered to express foreign, prokaryotic genes. T/F
false
ll restriction enzymes produce short stretches of single-stranded DNA called "sticky ends." T/F
false
What is unique about the DNA polymerase in PCR? It synthesizes DNA from the 3' direction to the 5' direction. It does not require primers. It can separate strands of DNA. It can withstand the high temperatures needed for PCR.
it can withstand the high temperatures of pcr
Which of the following is NOT true of the polymerase chain reaction (PCR)? A heat-stable DNA polymerase is used in the reaction process. Short pieces of DNA called primers are added to the reaction mixtures. Billions of copies of a DNA sequence are made in a few hours. Large amounts of DNA must be isolated from the source organism. An automated thermocycler is used to heat and cool the reaction samples.
large amounts of DNA must be isolated from the source organism
In the blue-white screening procedure, bacteria that are transformed with recombinant plasmid and cultured in media containing ampicillin and X-gal will __________. produce white colonies grow more rapidly than cells without recombinant DNA not grow in this medium produce blue colonies produce the enzyme beta-galactosidase
produce white colonies
Which of the following is NOT an advantage of obtaining the protein product called human growth hormone by recombinant DNA technology rather than extraction from cadavers?
production of endotoxins
Restriction enzymes ________.
recognize palindromic double-stranded sequences of DNA and cut the DNA in a specific location
Which of the following cuts DNA at specific sequences? plasmids restriction enzyme DNA ligase
restriction enzymes
Which of these statements is true for restriction enzymes? A different restriction enzyme must be used to open the vector DNA than to excise the gene sequence to be cloned. Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA. A given restriction enzyme will always recognize the same DNA sequence, but it will cut differently depending on the species of origin of the DNA. Any restriction enzyme can cut any piece of DNA. Each restriction enzyme is able to make a staggered cut at its recognition site.
restriction enzymes are useful in genetic engineering when they make staggered cuts in dna
the shotgun sequencing technique is used to
sequence entire genomes
Which of the following statements about PCR is true? The number of DNA doubles after each cycle. After each round of PCR, you will have one new strand of target DNA. The phosphodiester bond between each nucleotide is broken during the denaturation step. After 30 rounds of PCR, the target DNA has been amplified several thousand times.
the number of dna doubles after each cycle
During the Southern blotting technique, what is the purpose of transferring the DNA fragments from the gel to a nitrocellulose filter? This step prepares the DNA fragments for PCR. This step selects and transfers only the genes of interest. This step separates the two complementary DNA strands. This step attaches the DNA fragments to a permanent substrate, which then can be probed. This step prepares the DNA for digestion by restriction enzymes.
this step attaches the DNA fragments to a permanent substrate which then can be probed
Why must the recipient plasmid be cut with the same restriction enzyme? to prevent the donor from receiving the same genetic information to allow for a site in the plasmid for the donor DNA to attach to remove the donor DNA from the plasmid all of the above none of the above
to allow for a site in the plasmid for the donor dna to attach
Which of the following is NOT a purpose of genetic modification? to modify the characteristics of an organism to create proteins used in vaccines (e.g., hepatitis B vaccine) to create multiple copies of a gene of interest to create hormones such as insulin or human growth hormone to remove antibiotic resistant plasmids from bacteria
to remove antibiotic resistant plasmids from bacteria
E. coli may pick up a recombinant plasmid from a solution by __________.
transformation
The basic steps to genetically modify a cell are listed below. Which step would come LAST? restriction digestion of gene restriction digestion of vector ligation transformation
transformation
In protoplast fusion, a chemical can induce fusion between the two wall-less cells. T/F
true
All of the following are benefits and improvements made possible by recombinant DNA technology EXCEPT __________. improved weed and pest control development of genetic screening procedures for early detection of genetic diseases use of baker's yeast to produce bread development of new, safer vaccines
use of bakers yeast to produce bread