chapter 9 review

probe

A carefully chosen section of single-stranded DNA that is labeled and used to determine whether bacterial colonies contain a gene of interest is referred to as a DNA __________.

should have a gene or genes that allows for selection of transformed host cells

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

DNA fingerprinting

A method using restriction fragment length polymorphisms to identify bacterial or viral pathogens is __________.

false

All restriction enzymes produce short stretches of single-stranded DNA called "sticky ends." T/F

only the bacteria with the plasmid will grow

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, __________. only the bacteria with the plasmid will grow only the ampicillin-sensitive bacteria will grow only the lactose-positive bacteria will grow no bacteria will grow all gram-negative bacteria will grow

ampicillin resistant but do not contain the new gene

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 sensitive and can hydrolyze X-gal ampicillin resistant and contain the gene of interest ampicillin resistant but do not contain the new gene ampicillin sensitive and cannot hydrolyze X-gal

DNA fragments

DNA fingerprints are actually __________. DNA fragments genes cDNA RNA

This step attaches the DNA fragments to a permanent substrate, which then can be probed.

During the Southern blotting technique, what is the purpose of transferring the DNA fragments from the gel to a nitrocellulose filter? This step separates the two complementary DNA strands. This step prepares the DNA fragments for PCR. 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 selects and transfers only the genes of interest.

transformation

E. coli may pick up a recombinant plasmid from a solution by __________. transformation transduction protoplast fusion conjugation

inserted into the T-DNA region of the Ti plasmid of A. tumefaciens

For Agrobacterium tumefaciens to be used to introduce foreign DNA into a plant cell, that DNA must first be __________. inserted into the main chromosome of A. tumefaciens isolated from the crown gall using the appropriate restriction enzyme 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 T-DNA region of the Ti plasmid of A. tumefaciens

calcium chloride and heat shock can be used

For the introduction of a genetically modified plasmid into E. coli, __________. no treatment is needed, because the cells are naturally competent protoplast fusion must be used calcium chloride and heat shock can be used microinjection must be used a gene gun must be used

base-pairing would occur but the sugar phosphate backbone would not be connected

If DNA ligase were NOT used in the creation of a recombinant plasmid, __________. hydrogen bonds between complementary bases could not form links between adenine and thymine would not occur links between guanine and cytosine would not occur 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

true

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

transformation

If a recombinant plasmid is put in solution with E. coli, the bacteria may pick up the plasmid by __________. conjugation protoplast fusion transformation transduction

after exposure to 94∘C

In PCR, it is important to use Taq DNA polymerase, as opposed to other DNA polymerases. This is because Taq is capable of synthesizing DNA _________. at 55∘C after exposure to 94∘C at 94∘C from user-provided DNA and primers

make direct selection of a clone possible

In genetic engineering, antibiotic resistance genes are often cloned into a vector to __________. enhance survival of the cloned cell select for cells that cannot grow make direct selection of a clone possible kill bacteria

allow selection for bacteria containing the vector

In genetic engineering, antibiotic-resistance genes are usually cloned into vectors to __________. allow selection for bacteria containing the vector kill the recombinant organisms select for cells that cannot grow select for cells having undergone spontaneous mutation

destroy bacteriophage DNA

In nature, the function of restriction enzymes is to __________. destroy bacteriophage DNA destroy foreign DNA in animal cells cut plasmids splice DNA in a cell

produce white colonies

In the blue-white screening procedure, bacteria that are transformed with recombinant plasmid and cultured in media containing ampicillin and X-gal will __________. not grow in this medium produce blue colonies grow more rapidly than cells without recombinant DNA produce white colonies produce the enzyme beta-galactosidase

true

Many genetically modified bacteria are programmed with a self-destructive gene that will eventually destroy the organism.

shuttle

Plasmids 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.

false

Real-time PCR differs from traditional PCR in that real-time PCR amplification is monitored by gel electrophoresis.

polymerase chain reaction

Recombinant DNA can be introduced into a host cell by any of the following methods EXCEPT __________. electroporation protoplast fusion transformation microinjection polymerase chain reaction

identify particular sequences of DNA

Southern blotting is used to __________. select for antibiotic-resistant organisms identify specific proteins identify particular sequences of DNA identify particular sequences of RNA

Eukaryotic genes contain introns, which prokaryotic cells cannot remove.

Special considerations must be taken when using bacteria to produce a eukaryotic protein. What is the cause for this additional difficulty? Eukaryotic genes contain introns, which prokaryotic cells cannot remove. Translation in prokaryotes is very different from translation in eukaryotes. Prokaryotic DNA contains different nucleotides. Transcription is in prokaryotes is very different from transcription in eukaryotes.

bioinformatics

The branch of science that studies the function of genes through computer-assisted analysis is __________.

splice exons together

The following steps are necessary to clone eukaryotic genes in bacteria. What is the third step? remove introns transcription reverse transcription of mRNA splice exons together

transformation

The introduction of external pieces of "naked" DNA from solution into a cell is referred to as __________.

sequence entire genomes

The shotgun sequencing technique is used to __________. sequence entire genomes locate genes make an artificial chromosome cut chromosomes into fragments

cannot remove introns

To express a human gene in a bacterium, cDNA must be made because bacteria __________. splice RNA cannot remove introns have reverse transcriptase usually destroy human DNA

true

Viral DNA is an important cloning vector because it can typically be combined with relatively large pieces of DNA.

true

When bacteria are genetically modified to produce a protein product, technical difficulties arise because that product is NOT always secreted from the cell. T/F

associate by complementary base pairing and hydrogen bonds

When two DNA pieces cut with the same restriction enzyme are combined, sticky ends will __________. associate because of DNA ligase not associate associate by complementary base pairing and hydrogen bonds associate by covalent bonds associate only if they are double-stranded

a culture of genetically identical cells

Which of the following best describes a clone in the context of genetic modification procedures? a vector, once it contains a copy of the gene of interest a culture of genetically identical cells a cell that is genetically identical to its parent an identical copy of the gene of interest

Bacteria now produce hGH.

Which of the following best describes how recombinant DNA technology currently helps patients who do NOT produce adequate amounts of growth hormone (hGH)—a condition that otherwise leads to stunted growth? Recombinant vectors are used to stimulate hGH production in these patients. Bacteria now produce hGH. Recombinant vectors now produce hGH. Bacteria now produce rDNA coding for hGH.

To provide a structure from which DNA can be synthesized

Which of the following best describes the purpose of primers in PCR? To activate DNA polymerase to replicate DNA To separate double-stranded DNA into single strands To provide a structure from which DNA can be synthesized To provide a template for free nucleotides

Cells usually won't copy an isolated gene sequence.

Which of the following best describes why a vector is used in genetic modification procedures? The vector ensures that the clone remains pure. Cells usually won't copy an isolated gene sequence. The gene of interest must be isolated from adjacent genes. The clone must be able to produce proteins from the rDNA containing the gene of interest.

to remove antibiotic resistant plasmids from bacteria

Which of the following is NOT a purpose of genetic modification? to create hormones such as insulin or human growth hormone to create multiple copies of a gene of interest to create proteins used in vaccines (e.g., hepatitis B vaccine) to remove antibiotic resistant plasmids from bacteria to modify the characteristics of an organism

addition of heat-stable DNA polymerase

Which of the following is NOT a step in Southern blotting? addition of a radioactive probe made from the gene of interest digestion of sample DNA with restriction enzyme addition of heat-stable DNA polymerase transfer of DNA fragments to filters separation of DNA fragments by gel electrophoresis

production of endotoxins

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? speed production of endotoxins purity cross contamination cost-effectiveness

Large amounts of DNA must be isolated from the source organism.

Which of the following is NOT true of the polymerase chain reaction (PCR)? Short pieces of DNA called primers are added to the reaction mixtures. A heat-stable DNA polymerase is used in the reaction process. An automated thermocycler is used to heat and cool the reaction samples. Large amounts of DNA must be isolated from the source organism. Billions of copies of a DNA sequence are made in a few hours.

RNA interference

Which of the following might specifically be used as part of a reverse-genetics approach to studying a gene? Ti plasmid PCR Southern blotting RNA interference reverse transcriptase

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).

Which of the following statements correctly differentiates a genomic library from a cDNA library? 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 genomic library contains only noncoding DNA sequences, whereas a cDNA library contains only coding sequences. 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.

PCR is used to make copies of DNA in vitro.

Which of the following statements is true regarding the polymerase chain reaction (PCR)? PCR reactions take place at room temperature. PCR is used to make copies of DNA in vitro. E. coli's DNA polymerase is used to copy the target DNA. You do not need to know any of the sequence you want to amplify using PCR.

Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA.

Which of these statements is true for restriction enzymes? Any restriction enzyme can cut any piece of DNA. A different restriction enzyme must be used to open the vector DNA than to excise the gene sequence to be cloned. 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. Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA. Each restriction enzyme is able to make a staggered cut at its recognition site.

PCR

__________ is a technique used to quickly amplify specific sequences of DNA.

an mRNA template

cDNA is made from __________. a vector template a protein template an mRNA template a ribosomal DNA template

D, C, A, E, B

put the following into the correct order A. the plasmid is taken up by a bacterium B. a single plant cell is chosen to produce a plant that now produces Bt toxin C. the gene for Bt toxin is isolated from the bacterium and inserted into the plasmid D. the Ti plasmid is isolated and prepared for the insertion of foreign DNA E. the bacterium is used to introduce the Bt toxin gene into the chromosome of plant cells