Microbiology - Chapter 9

Which of the following places the steps in the PCR procedure in the correct order? 1) Incubate at 94°C to denature DNA strands; 2) Incubate at 72°C for DNA synthesis; 3) Incubate at 60°C for primer hybridization.

1,3,2

How many pieces will EcoRI produce from the plasmid shown in the figure?

2

What is the temperature used for the extension step? 60 °C 72 °C 94 °C

72 °C

What is the sequence of the temperatures of a typical PCR reaction?

94 °C, 60 °C, 72 °C

Which of the following methods could be used to identify the source of an outbreak? production of a recombinant protein artificial selection DNA fingerprinting reverse genetics

DNA fingerprinting

Suppose the thermocycler is INCORRECTLY programmed to omit the 72C step in each cycle of an otherwise normal PCR run. Which of the following would most likely occur? DNA polymerase would synthesize DNA more slowly. DNA polymerase would be active at 94∘∘C. Primers would NOT bind to DNA template strands. DNA template strands would bind to each other.

DNA polymerase would synthesize DNA more slowly.

T/F: The practice of breeding plants and animals for desirable traits, such as high crop yield, is called natural selection.

False

You want to determine whether a person has a certain mutant gene. The process involves using a primer and a heat-stable DNA polymerase. This process is PCR. transformation. restriction mapping. translation. site-directed mutagenesis.

PCR

Why is PCR a valuable technique? PCR stimulates transcription of genes (DNA). PCR creates large amounts of DNA from minute source quantities. PCR separates DNA from crude mixtures of other biomolecules. PCR harvests small quantities of DNA.

PCR creates large amounts of DNA from minute source quantities.

Which of the following are used to silence specific genes and hold promise for treating cancer or viral diseases, such as hepatitis B? complementary DNA (cDNA) DNA fingerprinting tumor-inducing plasmids (Ti plasmids) RNA interference (RNAi) reverse transcriptase PCR (rtPCR)

RNA interference (RNAi)

Which of the following is an application that uses PCR? Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism Providing enough DNA for cloning into another organism Sequencing a gene Diagnosing a disease

Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism

What does a thermocycler do? Monitors the synthesis of DNA Adds reagents to facilitate the PCR run Subjects samples to temperature changes Purifies DNA from a crude sample

Subjects samples to temperature changes

How do the strands separate during PCR? The primers separate the strands during the annealing step. The high heat of the denaturation step breaks the hydrogen bonds between the two strands. The cycling of the temperatures breaks the hydrogen bonds between the two strands. The DNA polymerase breaks the hydrogen bonds between the two strands.

The high heat of the denaturation step breaks the hydrogen bonds between the two strands.

A source of heat-stable DNA polymerase is Bacillus thuringiensis. Thermus aquaticus. Saccharomyces cerevisiae. Agrobacterium tumefaciens. Pseudomonas.

Thermus aquaticus

Which statement best describes restriction enzymes? They are necessary for the polymerase chain reaction (PCR) to occur. They randomly cut DNA molecules to generate numerous fragments. They can cut only circular plasmid DNA. They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.

They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences. Submit

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

To provide a structure from which DNA can be synthesized

Self-replicating DNA used to transmit a gene from one organism to another is a library. vector. clone. Southern blot. PCR.

Vector

A restriction fragment is cDNA. a segment of mRNA. a segment of DNA. a gene. a segment of tRNA.

a segment of DNA.

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 at 94∘∘C from user-provided DNA and primers after exposure to 94∘∘C

after exposure to 94.

A population of cells carrying a desired plasmid is called a PCR. library. vector. Southern blot. clone.

clone

Which of the following pairings of recombinant DNA techniques and applications does NOT match? gene therapy: replacing a defective gene PCR: making many copies of a segment of DNA gene silencing: production of subunit vaccines genetic modification of yeast: production of purified insulin

gene silencing: production of subunit vaccines

The random shotgun method is used in genome sequencing. amplification of unknown DNA. transforming plant cells with recombinant DNA. forensic microbiology. RFLP analysis.

genome sequencing

Which of the following is NOT a desired characteristic of DNA vectors used in gene cloning procedures? may replicate in several species large size self-replication has a selectable marker circular form of DNA or integrates into the host chromosome

large size

The study of genetic material taken directly from the environment is bioinformatics. proteomics. forensic microbiology. metagenomics. reverse genetics.

metagenomics.

In the figure, the gene that allows the plasmid to be self-replicating is HindIII. EcoRI. ampR. ori. lacZ.

ori

PCR stands for polymerase chain reaction. polymerization copying rapidly. polymerase copy reaction.

polymerase chain reaction.

Assume you have discovered a cell that produces a lipase that works in cold water for a laundry additive. You can increase the efficiency of this enzyme by changing one amino acid. This is done by irradiating the cells. site-directed mutagenesis. selective breeding. enrichment. selection.

site-directed mutagenesis.

Gene silencing involves all of the following EXCEPT small interfering RNAs. production of double stranded RNAs. small interfering RNA binding to a gene promoter. RNA-induced silencing complex. Dicer.

small interfering RNA binding to a gene promoter.

Each step of the polymerase chain reaction is associated with a particular temperature. Match the temperatures in the left column with the appropriate PCR stage on the right.

72C = DNA extension 55C= Primer annealing 94C= DNA denaturation

The following tiles indicate the first five thermocycler steps in a PCR run. Arrange them in the correct order.

94 for 1 minutes 55 for 1 minutes 72 for 1 minute 94 for 1 minutes 55 for 1 minute

T/F: The term biotechnology refers exclusively to the use of genetically engineered organisms for the production of desired products.

False

What is a thermocycler? The process of cycling through the different temperatures of a PCR reaction 30 times The name for the DNA primers used in a PCR reaction The special DNA polymerase, used in a PCR reaction, that can tolerate the high temperatures The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR

The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR

Which of the following is NOT a property of useful vectors? They must be small enough to allow them to be manipulated prior to injection. They must be able to self-replicate. They must have properties that allow their survival in the host cell. They always contain only one gene.

They always contain only one gene.

After the 94C step, why must the thermocycler reduce the temperature to 55C? To allow the DNA template strands to bind to each other To separate the DNA template strands To allow primers to bind to the DNA template strands To optimize DNA polymerase activity

To allow primers to bind to the DNA template strands

What is the end goal of PCR? To allow cells to make DNA faster, thereby growing faster To quickly increase the number of copies of a specific DNA sequence To increase the pool of different DNA sequences

To quickly increase the number of copies of a specific DNA sequence

In the Southern blot technique, which of the following is NOT required? electrophoresis to separate fragments. addition of heat-stable DNA polymerase to amplify DNA. addition of a labeled probe to identify the gene of interest. restriction enzyme digestion of DNA. transfer of DNA to nitrocellulose.

addition of heat-stable DNA polymerase to amplify DNA

Restriction enzymes are viral enzymes that destroy host DNA. bacterial enzymes that destroy phage DNA. animal enzymes that splice RNA. bacterial enzymes that splice DNA.

bacterial enzymes that destroy phage DNA.

The Human Genome Project, which was completed in 2003, was focused on determining the nucleotide sequence of the entire human genome. identifying all of the genes in the human genome. determining all of the proteins encoded by the human genome. cloning all of the genes of the human genome. finding a cure for all human genetic disorders.

determining the nucleotide sequence of the entire human genome.

The use of an antibiotic-resistance gene on a plasmid used in genetic engineering makes direct selection possible. the recombinant cell dangerous. the recombinant cell unable to survive. replica plating possible. All of the answers are correct.

direct selection possible.

Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell's membrane? transformation electroporation heat shock protoplast fusion

electroporation

Which of the following applications of recombinant DNA technology is NOT controversial? genetic food modification biological weapons development metagenomics genetic screening

metagenomics.

Biotechnology involves the use of animal cells to make vaccines.development of disease-resistant crop plants. use of microorganisms to make desired products and the use of animal cells to make vaccines. use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants. use of microorganisms to make desired products.

use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants.

Which statement regarding agricultural biotechnology is FALSE? Scientists have used gene silencing to create tomatoes with a longer shelf life. Scientists have created plants that produce an insect toxin originally found in bacteria. Scientists have created plants that are resistant to herbicides by using a mutant enzyme gene from Salmonella. Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.

Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells. Submit

Which of the following best describes why PCR protocols contain numerous cycles of the denaturation/annealing/extension steps? The denaturation step of each cycle only separates some of the source DNA. By performing numerous cycles, PCR generates copies of all the target sequences. Each cycle of PCR allows Taq polymerase to partially synthesize the target sequence. Numerous cycles are necessary for the target sequence to be fully copied. Each cycle of PCR incorporates some of the included primers into amplicons. Numerous cycles of PCR are required to ensure all primers are incorporated. Each cycle of PCR doubles the amount of DNA synthesized, but the number of copies starts out small. Numerous cycles are required to produce a sufficient number of copies.

Each cycle of PCR doubles the amount of DNA synthesized, but the number of copies starts out small. Numerous cycles are required to produce a sufficient number of copies.

Which of the following statements about recombinant DNA technology is FALSE? It allows researchers to make protein products of a gene. It allows researchers to make many copies of a gene of interest. It can be used to screen individuals for many different types of genetic diseases. It has limited application because genes of interest cannot be moved from one type of cell to another.

It has limited application because genes of interest cannot be moved from one type of cell to another.

Which of the following methods would be used to introduce the plasmid shown in the figure into E. coli? transformation microinjection gene guns Ti plasmids and Agrobacterium

Transformation

T/F: A shuttle vector is a plasmid that is used to move pieces of DNA among organisms, such as bacterial, fungal, and plant cells.

True

T/F: Bioinformatics is the use of computer technology to compare and analyze genome sequence.

True

T/F: In recombinant DNA technology, a vector is a self-replicating segment of DNA, such as a plasmid or viral genome.

True

T/F: One of the first commercial successes of recombinant DNA technology was the production of human insulin using genetically engineered E. coli.

True

T/F: The Bt toxin derived from Bacillus thuringiensis has been introduced into some crop plants to make them resistant to insect destruction.

True