Microbiology Ch 9 biotechnology and Recombinant DNA
A good cloning vector: A. should have a gene or genes that allows for selection of transformed host cells. B. should not be able to be cut by more than one restriction enzyme. C. should be readily degraded in the host. D. should not be capable of replication. E. should be large
A
How does a bacterial cell protect its own DNA from restriction enzymes? A. by adding methyl groups to adenines and cytosines B. by reinforcing bacterial DNA structure with covalent phosphodiester bonds C. adding histones to protect the double-stranded DNA D. by forming "sticky ends" of bacterial DNA to prevent the enzyme from attaching E. using DNA ligase to seal the bacterial DNA into a closed circle
A
In recombinant DNA technology, plasmids may be used to: A. introduce foreign DNA into bacteria B. cut DNA at a specific location C. introduce foreign DNA into human cells D. activate restriction enzymes
A
Plasmids occur naturally in: A. bacteria B. viruses C. animal cells D. plant cells
A
What is a cloning vector? A. an agent, such as a plasmid, used to transfer DNA from an in vitro solution into a living cell B. the sticky end of a DNA fragment C. the laboratory apparatus used to clone genes D. a DNA probe used to locate a particular gene in the genome E. the enzyme that cuts DNA into restriction fragments
A
Which of the technologies listed below is a valuable method for mass-producing drugs and other useful proteins? A. recombinant DNA technology B. transgenic technology C. biotechnology D. gene targeting
A
Which of the tools below is used to cut the gene from its normal location? A. restriction enzyme B. plasmid C. bacteriophage D. vector
A
From the list BELOW, which of the following is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? 1. Transform bacteria with recombinant DNA molecule 2. Cut the plasmid DNA using restriction enzymes 3. Extract plasmid DNA from bacterial cells 4. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments 5. Use ligase to seal plasmid DNA to nonplasmid DNA A) 4, 5, 1, 2, 3 B) 3, 2, 4, 5, 1 C) 3, 4, 5, 1, 2 D) 2, 3, 5, 4, 1 E) 1, 2, 4, 3, 5
B
The restriction enzyme used in constructing hybrid molecules of certain gene sequences and plasmid DNA acts by A. transcribing plasmid DNA into a transformed molecule. B. opening DNA molecules at specific sites, leaving sticky ends exposed. C. binding human genes to bacterial plasmids. D. allowing a hybrid plasmid DNA into a transformed molecule. E. sealing plasmid DNA and foreign DNA into a closed circle.
B
When two DNA pieces cut with the same restriction enzyme are combined, sticky ends will: A. not associate. B. associate only if they are double stranded. C. associate by covalent bonds. D. associate due to DNA ligase. E. associate by complementary base pairing and hydrogen bonds.
B
___ seals a nick in a strand of DNA by creating a sugar phosphate bond between the adjacent, disjointed nucleotides. A. DNAse B. DNA ligase C. Restriction endonuclease D. EcoRI E. A and C
B
All of the following are true of the polymerase chain reaction (PCR) except: A. A heat-stable DNA polymerase is used in the reaction process. B. Short pieces of DNA called primers are added to the reaction mixtures. C. Large amounts of DNA must be isolated from the source organism. D. Billions of copies of a DNA sequence are made in a few hours. E. An automated thermocycler is used to heat and cool the reaction samples
C
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: A. only the lactose-positive bacteria will grow. B. only the ampicillin-sensitive bacteria will grow. C. only the bacteria with the plasmid will grow. D. all bacteria will grow. E. no bacteria will grow.
C
Bacteria containing recombinant plasmids are often identified by which process? A. removing the DNA of all cells in a culture to see which cells have plasmids B. examining the cells with an electron microscope C. exposing the bacteria to an antibiotic that kills the cells lacking the plasmid D. producing antibodies specific for each bacterium containing a recombinant plasmid E. using radioactive tracers to locate the plasmids
C
What two enzymes are needed to produce recombinant DNA? A. endonuclease, transcriptase B. DNA polymerase, topoisomerase C. restriction enzyme, ligase D. polymerase, ligase E. transcriptase, ligase
C
Gel electrophoresis separates DNA fragments according to their: A. percentage of labeled nucleotides B. base sequence C. number of attached primers D. size
D
Place in order the following steps involved in PCR: (1) newly synthesized strands act as templates (2) DNA template, nucleotide bases, DNA primers and polymerase added (3) temperature lowered, base pairing between primers and template (4) heat separates strands of target DNA (5) complementary new strand synthesized A. 1 - 2 - 3 - 4 - 5 B. 3 - 5 - 4 - 2 - 1 C. 3 - 2 - 4 - 5 - 1 D. 2 - 4 - 3 - 5 - 1
D
Which of the following techniques is similar to a molecular "copy machine" for DNA? A. gel electrophoresis B. restriction enzymes C. DNA sequencing D. polymerase chain reaction (PCR)
D
What is the genetic function of restriction enzyme? A. adds new nucleotides to the growing strand of DNA B. joins nucleotides during replication C. repairs breaks in sugar-phosphate backbones D. joins nucleotides during transcription E. cleaves nucleic acids at specific sites
E
Which of the following is true for restriction enzymes? A. 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. B. Each restriction enzyme known is able to make a staggered cut at its recognition site. C. Any restriction enzyme can cut any piece of DNA. D. A different restriction enzyme must be used to open the vector DNA than to excise the gene sequence to be cloned. E. Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA
E