Exam 2

Created by sjleininger 

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What are the products of semiconservative replication for a double-stranded DNA molecule?

a. One double-stranded DNA molecule consisting of one parental strand and one daughter strand.
b. Two double-stranded DNA molecules, one consisting of two parental strands and the other consisting of two daughter strands.
c. Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand.
d. One double-stranded DNA molecule, consisting of two daughter strands.

c. Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand.

Why is DNA replication essential for a cell?

a. An organism must copy its DNA to pass genetic information to its offspring.
b. All organisms require two copies of DNA.
c. It allows the organism to repair any mistakes.
d. Because DNA is double-stranded.

a. An organism must copy its DNA to pass genetic information to its offspring.

What is the function of the parental DNA in replication?

a. It is passed into the offspring of the parent.
b. It gives the cell two complete copies of the DNA.
c. It allows for the DNA to be circular.
d. It serves as the template for DNA replication.

d. It serves as the template for DNA replication.

Which of the following is a DNA strand complementary to CGA ATC AGC?

a. GCT TAG TCG
b. CGA ATC AGC
c. GCU UAG UCG
d.TAG GCT GAT

a. GCT TAG TCG

Transcription produces which of the following?

a. mRNA
b. rRNA
c. tRNA
d. mRNA and tRNA
e. mRNA and rRNA
f. mRNA, tRNA, and rRNA are all produced by transcription.

f. mRNA, tRNA, and rRNA are all produced by transcription.

According to the animation, which of the following makes mRNA from the information stored in a DNA template?

a. DNA polymerase
b. tRNA
c. Ribosomes
d. RNA polymerase

d. RNA polymerase

Ribosomes contain which of the following?

a. mRNA, tRNA, and rRNA are all found as part of the ribosome.
b. rRNA
c. tRNA
d. mRNA

b. rRNA

Which of the following is involved in bringing amino acids to the ribosomes?

a. mRNA
b. mRNA, tRNA, and rRNA are all involved in transporting amino acids to the ribosomes.
c. rRNA
d. tRNA

d. tRNA

Which of the following can be translated into protein?

a. rRNA
b. mRNA, tRNA, and rRNA are all translated into protein.
c. mRNA
d. tRNA

c. mRNA

Which of the following statements concerning transcription is true?

a. Promoter sequences signal the end of a gene and mark the place where transcription stops.
b. During transcription, entire chromosomes are copied because the starting position of genes is unknown.
c. All types of RNA in the cell are synthesized by transcription, which uses a portion of DNA as a template for copying.
d. Transcription is the process whereby identical copies of DNA are made in preparation for cell division.

c. All types of RNA in the cell are synthesized by transcription, which uses a portion of DNA as a template for copying.

What results from the process of translation?

a. tRNA
b. mRNA
c. A polypeptide
d. Ribosomes

c. A polypeptide

How is bacterial translation different from eukaryotic translation?

a. mRNA is read 3' to 5'.
b. Bacteria can begin translation before transcription has terminated.
c. Bacterial translation does not involve ribosomes.

b. Bacteria can begin translation before transcription has terminated.

According to the animation, ribosomes move along the mRNA in which direction?

a. 5' to 3'
b. 3' to 5'
c. Either 5' to 3' or 3' to 5'

a. 5' to 3'

Which of the following best describes the flow of information in cells?

a. Ribosomes make proteins by randomly linking amino acids together.
b. DNA acts as a messenger. It binds to a ribosome and provides instructions for making protein.
c. DNA is converted to RNA, which is then converted to protein.
d. mRNA is made by copying specific regions of DNA called genes. Ribosomes use mRNA as instructions, which provide a code specifying the order of amino acids in a protein.

d. mRNA is made by copying specific regions of DNA called genes. Ribosomes use mRNA as instructions, which provide a code specifying the order of amino acids in a protein.

Which of the following genetic elements is transcribed into a single mRNA?

a. The inducer
b. The repressor
c. The promoter
d. The operator
e. The structural genes

e. The structural genes

Which operons are always transcribed unless deactivated?

a. Inducible operons
b. Repressible operons
c. Inducible and repressible operons

b. Repressible operons

Which operons are never transcribed unless activated?

a. Inducible operons
b. Repressible operons
c. Inducible and repressible operons

a. Inducible operons

According to the animation, where on the DNA strand does a repressor bind?

a. The inducer
b. The operator
c. The promoter
d. The structural genes

b. The operator

A recombinant cell

a. is the result of a cell dividing.
b. is a cell that receives DNA from an outside source and incorporates it into its own.
c. donates DNA into a new cell.

b. is a cell that receives DNA from an outside source and incorporates it into its own.

What is the hallmark of all horizontal gene transfers?

a. Transfer of DNA using a virus
b. Transfer of DNA between organisms of the same generation
c. Transfer of DNA from parent to offspring
d. The use of plasmids

b. Transfer of DNA between organisms of the same generation

Which of the following is an example of horizontal gene transfer in bacteria?

a. Conjugation
b. Transduction
c. Transduction, conjugation, and transformation
d. Transformation
e. Conjugation and transformation

c. Transduction, conjugation, and transformation

Bacterial conjugation is often referred to as bacterial sex. Why is this term inaccurate?

a. Bacteria are neither male nor female.
b. Sex is a phenomenon only seen in animals.
c. Conjugation does not result in the formation of new offspring.
d. It does not require two cells to occur.

c. Conjugation does not result in the formation of new offspring.

What must occur for bacterial conjugation to take place?

a. The cells must come into contact with each other.
b. Each cell must contain a plasmid.
c. One of the cells must be E. coli.
d. The cells must transfer RNA.

a. The cells must come into contact with each other.

Which statement about conjugation is false?

a. Conjugation is a process of bacterial reproduction.
b. E. coli is the model for bacterial conjugation.
c. After conjugation, each cell involved has a copy of the shared DNA.

a. Conjugation is a process of bacterial reproduction.

Based on the animation, what is transferred during bacterial conjugation?

a. RNA
b. A conjugation pilus
c. A bacterial plasmid
d. A bacterial chromosome

c. A bacterial plasmid

Competent cells are cells that

a. can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.
b. are also considered "rough-strain" based on colony phenotype.
c. have the ability to produce capsules.
d. are killed by heat.

a. can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.

Mice that are injected with only the R strain of Streptococcus pneumoniae

a. become sick for prolonged periods of time.
b. stay healthy, because their immune systems can kill this strain easily.
c. are killed, because R strain cells are deadly.

b. stay healthy, because their immune systems can kill this strain easily.

What characteristic of the S strain allows it to evade the immune system of the mice?

a. They are naturally competent.
b. The cells have a capsule.
c. They are resistant to heat.
d. They are genetically engineered to be resistant to killing.

b. The cells have a capsule.

What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells?

a. The S strain fused with the R strain, making it resistant.
b. The S strain was revived by the presence of the host's immune system.
c. The R strain cells picked up the capsules from the S strain cells.
d. The R strain picked up the S strain DNA, enabling it to produce a capsule.

d. The R strain picked up the S strain DNA, enabling it to produce a capsule.

Which finding is most surprising from Griffith's experiments?

a. R strain cells fail to produce a capsule.
b. S strains are able to escape phagocytosis.
c. S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.
d. S strain cells kill the mice.

c. S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.

What is unique about transduction compared to normal bacteriophage infection?

a. Transduction transfers DNA from the chromosome of one cell to another.
b. The bacteriophage does not erupt from an infected cell during transduction.
c. The bacteriophage takes fragments of the cell with it during transduction.

a. Transduction transfers DNA from the chromosome of one cell to another.

How is generalized transduction different from specialized transduction?

a. Generalized transduction is initiated by a lysogenic bacteriophage; specialized transduction is initiated by a lytic phage.
b. Only one specific host gene is transferred in both specialized transduction and generalized transduction.
c. Specialized transduction uses animal viruses instead of bacteriophage.
d. Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.

d. Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.

A transducing phage

a. cannot infect new host cells.
b. is a lysogenic bacteriophage.
c. contains fragments of the host chromosome instead of the viral genome.
d. has a viral coat made of host proteins.

c. contains fragments of the host chromosome instead of the viral genome.

When a transducing phage interacts with a new host cell,

a. the DNA from the previous host can recombine with the new host chromosome.
b. it will cause the new cell to produce more transducing phage.
c. the new host cell will be lysed.

a. the DNA from the previous host can recombine with the new host chromosome.

Which of the following is a method of vertical gene transmission?

a. conjugation
b. cell division
c. transformation
d. transduction

b. cell division

Frederick Griffith did experiments on genetic transformation. Which of the following statements about his experiments is accurate?

a. Griffith used only pathogenic bacteria in his experiments.
b. The combination of living nonencapsulated bacteria and heat-killed encapsulated bacteria did not cause disease.
c. Griffith used bacteria in which the nonpathogenic strain was encapsulated but the pathogenic strain was not.
d. Griffith found that DNA released from dead (virulent) bacteria entered live (avirulent) bacteria and changed them genetically, causing them to become virulent.

d. Griffith found that DNA released from dead (virulent) bacteria entered live (avirulent) bacteria and changed them genetically, causing them to become virulent.

Which of the following does NOT accurately apply to the Ames test?

a. The test uses bacteria as mutagen carcinogen indicators.
b. The Ames test is based on the observation that reversions CANNOT occur in mutant bacteria.
c. The Ames test measures the reversion of histidine auxotrophs of Salmonella.
d. The test can be used to qualitatively test potential mutagens.

b. The Ames test is based on the observation that reversions CANNOT occur in mutant bacteria.

What is considered to be the average natural mutation rate that occurs during DNA replication?

a. One in every million nucleotides replicated.
b. One in every trillion nucleotides replicated.
c. One in every billion nucleotides replicated.
d. One in every ten thousand nucleotides replicated.

c. One in every billion nucleotides replicated.

A mutation that affects the genotype of the organism but not the phenotype is called a

a. nonsense mutation.
b. missense mutation.
c. frameshift mutation.
d. silent mutation.

d. silent mutation.

A base insertion or deletion in the translated region of the gene may lead to

a. missense mutation.
b. frameshift mutation.
c. nonsense mutation.
d. silent mutation.

b. frameshift mutation.

A base substitution that changes a codon coding for an amino acid to a stop codon is called a

a. frameshift mutation.
b. missense mutation.
c. silent mutation.
d. nonsense mutation.

d. nonsense mutation.

How frequently do silent mutations occur?

a. One out of every billion mutations
b. One out of every three mutations
c. Half of all mutations
d. One out of every million mutations

b. One out of every three mutations

Which of the following build(s) new strands of DNA?

a. The leading strand
b. DNA polymerases
c. The lagging strand
d. Parental DNA
e. The origins of replication

b. DNA polymerases

Which statement about DNA replication is CORRECT?

a. The lagging strand is one of the strands of parental DNA.
b. DNA ligase helps assemble the leading strand.
c. The lagging strand is built continuously.
d. The leading strand is built continuously, and the lagging strand is built in pieces.
e. The leading strand is one of the strands of parental DNA.

d. The leading strand is built continuously, and the lagging strand is built in pieces.

During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?

a. G
b. C
c. T
d. U
e. A

c. T

The molecule that seals the gaps between the pieces of DNA in the lagging strand is

a. RNA.
b. the replication fork.
c. the leading strand.
d. DNA polymerase.
e. DNA ligase.

e. DNA ligase.

Which statement about DNA replication is FALSE?

a. Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways.
b. The two strands of parental DNA are separated during DNA replication.
c. DNA polymerase builds a new strand by adding DNA nucleotides one at a time.
d. The lagging strand is made of a series of pieces that must be joined together to make a continuous strand.
e. DNA ligase adds nucleotides to the lagging strand.

e. DNA ligase adds nucleotides to the lagging strand.

Deleting or inserting one nucleotide pair in the middle of a gene is an example of which of the following?

a. base substitution
b. nonsense mutation
c. frameshift mutation
d. missense mutation

c. frameshift mutation

Transformation is the transfer of DNA from a donor to a recipient cell

a. by cell-to-cell contact.
b. as naked DNA in solution.
c. by a bacteriophage.
d. by sexual reproduction.
e. by crossing over.

b. as naked DNA in solution.

Genetic change in bacteria can be brought about by

a. transduction.
b. mutation.
c. conjugation.
d. transformation.
e. All of the answers are correct.

e. All of the answers are correct.

Which of the following statements regarding a bacterium that is R+ is false?

a. R+ can be transferred to a cell of the same species.
b. It possesses a plasmid.
c. It is F+.
d. It is resistant to certain drugs and heavy metals.
e. R+ can be transferred to a different species.

c. It is F+.

The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus, and the template is from a human cell. The DNA synthesized would be most similar to

a. human DNA.
b. T. aquaticus DNA.
c. a mixture of human and T. aquaticus DNA.
d. human RNA.
e. T. aquaticus RNA.

a. human DNA.

Based on the information in the table, prostate cancer is probably the result of which kind of mutation?

a. missense
b. nonsense
c. frameshift
d. analog
e. None of the answers is correct.

b. nonsense

If you knew the sequence of nucleotides within a gene, which one of the following could you determine with the most accuracy?

a. the primary structure of the protein
b. the secondary structure of the protein
c. the tertiary structure of the protein
d. the quaternary structure of the protein
e. The answer cannot be determined.

a. the primary structure of the protein

What is the end goal of PCR?

a. To increase the pool of different DNA sequences
b. To allow cells to make DNA faster, thereby growing faster
c. To quickly increase the number of copies of a specific DNA sequence

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

PCR stands for

a. polymerization copying rapidly.
b. polymerase chain reaction.
c. polymerase copy reaction.

b. polymerase chain reaction.

Which of the following is an application that uses PCR?

a. Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
b. Sequencing a gene
c. Providing enough DNA for cloning into another organism
d. Diagnosing a disease

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

What is the function of the primers in PCR?

a. They are the monomer building blocks from which the DNA strand is synthesized.
b. They provide energy for the DNA polymerization reactions.
c. They polymerize free nucleotides to form the new DNA strands.
d. They provide a 3' end for the DNA polymerase.

d. They provide a 3' end for the DNA polymerase.

In which direction does DNA polymerase synthesize the new DNA strand?

a. 5' to 3'
b. 3' to 5'
c. Both 5' to 3' and 3' to 5'

a. 5' to 3'

What provides the energy for DNA polymerization in a PCR reaction?

a. DNA polymerase
b. Deoxyribonucleoside triphosphates
c. Primers
d. Template DNA

b. Deoxyribonucleoside triphosphates

Why is DNA polymerase from Thermus aquaticus ideal for PCR?

a. It can synthesize DNA 5' to 3' and 3' to 5'.
b. It does not require primers.
c. It can withstand the high temperatures associated with PCR.
d. It does not require energy to polymerize DNA.

c. It can withstand the high temperatures associated with PCR.

What is the temperature used for the extension step?

a. 72 °C
b. 60 °C
c. 94 °C

a. 72 °C

How do the strands separate during PCR?

a. The primers separate the strands during the annealing step.
b. The DNA polymerase breaks the hydrogen bonds between the two strands.
c. The cycling of the temperatures breaks the hydrogen bonds between the two strands.
d. The high heat of the denaturation step breaks the hydrogen bonds between the two strands.

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

What is a thermocycler?

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

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

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

a. 94 °C, 72 °C, 60 °C
b. 94 °C, 60 °C, 72 °C
c. 72 °C, 60 °C, 94 °C
d. 72 °C, 94 °C, 60 °C
e. 60 °C, 72 °C, 94 °C

b. 94 °C, 60 °C, 72 °C

If you used a broken thermocycler that could not heat above 75°C, which of the following problems could you expect?

a. You would get more amplification than with a "normal" thermocycler.
b. You would get some significant amplification, but less than if you used a "normal" thermocycler.
c. You would not get any amplification of DNA.
d. You would get the same amount of amplification as with a "normal" thermocycler.

b. You would get some significant amplification, but less than if you used a "normal" thermocycler.

Which of the following provides the specificity of the PCR reaction?

a. primers
b. separated DNA strands
c. heating to 94°C
d. Taq polymerase

a. primers

A new arrow labeled "lengthens" could be added between __________.

a. "target DNA" → "DNA strands"
b. "primers" → "DNA strands"
c. "Taq polymerase" → "primers"
d. "target DNA" → "primers"

c. "Taq polymerase" → "primers"

How do restriction enzymes cut DNA sequences?

a. They cut DNA at sequences that have lots of adenine bases.
b. They have the ability to cut DNA randomly.
c. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.

c. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.

In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?

a. To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
b. To remove an undesirable gene
c. To insert a desirable gene
d. To replace a defective gene with a working gene

a. To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene

Which of the following attaches the target gene to a desired location?

a. DNA ligase
b. Plasmids
c. Restriction enzymes
d. Chromosomal DNA

a. DNA ligase

Why would a recombinant DNA molecule be inserted into a host cell?

a. It can protect the recombinant DNA.
b. Restriction enzymes can only be used inside of a cell.
c. It can be copied, transcribed, and translated into a desired protein.
d. Plasmids cannot be isolated outside of a host cell.

c. It can be copied, transcribed, and translated into a desired protein.

Which statement best describes restriction enzymes?

a. They can cut only circular plasmid DNA.
b. They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.
c. They randomly cut DNA molecules to generate numerous fragments.
d. They are necessary for the polymerase chain reaction (PCR) to occur.

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

Which of the following pairings of recombinant DNA techniques and applications does NOT match?

a. genetic modification of yeast: production of purified insulin
b. gene therapy: replacing a defective gene
c. PCR: making many copies of a segment of DNA
d. gene silencing: production of subunit vaccines

d. gene silencing: production of subunit vaccines

Why is baker's yeast useful for expressing genetically engineered genes?

a. The yeast cells are best suited for making human products for medical use.
b. Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.
c. Many inducible promoters from the yeast genome have been cloned, such as the lac operon.
d. The yeast cells do not secrete their protein products.

b. Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.

Which of the following methods could be used to identify the source of an outbreak?

a. DNA fingerprinting
b. reverse genetics
c. production of a recombinant protein
d. artificial selection

a. DNA fingerprinting

Which of the following statements about recombinant DNA technology is FALSE?

a. It allows researchers to make many copies of a gene of interest.
b. It can be used to screen individuals for many different types of genetic diseases.
c. It has limited application because genes of interest cannot be moved from one type of cell to another.
d. It allows researchers to make protein products of a gene.

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

Which of the following applications of recombinant DNA technology is NOT controversial?

a. genetic screening
b. biological weapons development
c. metagenomics
d. genetic food modification

c. metagenomics

Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium (!). Which of the following represents the correct sequence of procedures that you would use?


a. Transform the vector into the bacteria.
Amplify the gene using PCR.
Insert the gene into a plasmid vector.

b. Amplify the gene using PCR.
Transform the vector into the bacteria.
Insert the gene into a plasmid vector.

c. Amplify the gene using PCR.
Insert the gene into a plasmid vector.
Transform the vector into the bacteria.

d. Insert the gene into a plasmid vector.
Amplify the gene using PCR.
Transform the vector into the bacteria.

c. Amplify the gene using PCR.
Insert the gene into a plasmid vector.
Transform the vector into the bacteria.

Which statement regarding agricultural biotechnology is FALSE?

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

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

The reaction catalyzed by reverse transcriptase is

a. DNA → mRNA.
b. mRNA → cDNA.
c. mRNA → protein.
d. DNA → DNA.
e. tRNA → mRNA.

b. mRNA → cDNA.

Which of the following is an advantage of using E. coli to make a human gene product?

a. Endotoxin may be in the product.
b. It does not secrete most proteins.
c. Its genes are well known.
d. It cannot process introns.
e. None of the answers is correct.

c. Its genes are well known.

Biotechnology involves the

a. use of microorganisms to make desired products.
b. use of animal cells to make vaccines.
c. development of disease-resistant crop plants.
d. use of microorganisms to make desired products and the use of animal cells to make vaccines.
e. use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistanct crop plants.

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

The Human Genome Project, which was completed in 2003, was focused on

a. identifying all of the genes in the human genome.
b. determining the nucleotide sequence of the entire human genome.
c. determining all of the proteins encoded by the human genome.
d. finding a cure for all human genetic disorders.
e. cloning all of the genes of the human genome.

b. determining the nucleotide sequence of the entire human genome.

Place the following 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.

a. 1 3 2
b. 3 2 1
c. 2 1 3
d. 3 1 2
e. 1 2 3

a. 1 3 2

A source of heat-stable DNA polymerase is

a. Thermus aquaticus.
b. Bacillus thuringiensis.
c. Agrobacterium tumefaciens.
d. Saccharomyces cerevisiae.
e. Pseudomonas.

a. Thermus aquaticus.

The Pap test for cervical cancer involves microscopic examination of cervical cells for cancerous cells. A new, rapid diagnostic test to detect human papilloma virus (HPV) DNA before cancer develops is done without microscopic exam. The steps involved in this FastHPV test are listed below. What is the second step?

a. Add an RNA probe for HPV DNA.
b. add enzyme substrate.
c. Add enzyme-linked antibodies against DNA-RNA.
d. Lyse human cells.
e. The order is unimportant.

a. Add an RNA probe for HPV DNA.

PCR can be used to identify an unknown bacterium because

a. the RNA primer is specific.
b. DNA polymerase will replicate DNA.
c. DNA can be electrophoresed.
d. all cells have DNA.
e. all cells have RNA.

a. the RNA primer is specific.

Restriction enzymes are

a. bacterial enzymes that splice DNA.
b. viral enzymes that destroy host DNA.
c. bacterial enzymes that destroy phage DNA.
d. animal enzymes that splice RNA.

c. bacterial enzymes that destroy phage DNA.

Why are archaea and bacteria—both collections of prokaryotic organisms—grouped into different domains while organisms like fungi and animals are in the same domain?

a. Bacteria and archaea differ significantly in their intracellular organization and structure, but fungi and animals have similar intracellular structure.
b. The DNA sequences of bacteria and archaea are more different than animals and fungi.
c. Fungi and animals look much more similar than bacteria and archaea.
d. Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics.

d. Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics.

While working with a broth culture of archaea in the laboratory, you accidentally spill some of the microorganisms on yourself. Do you need to be concerned about developing an infection? Why or why not?

a. No; archaea are not pathogenic.
b. Yes; certain archaea can be pathogenic, so an infection could occur.
c. Yes; all infectious prokaryotes are archaea.
d. No; archaea are prokaryotic, so they cannot cause infection.

a. No; archaea are not pathogenic.

Which of the following methods could be used to differentiate between a member of domain Bacteria and a member of domain Archaea?

a. You could look for the presence of mitochondria.
b. You could see if the organism produces rRNA.
c. You could see if the organism can survive in an extreme environment.
d. You could look for the presence of peptidoglycan.
e. All of the above would work.
f. None of the above would work.

d. You could look for the presence of peptidoglycan.

Why is visualization not sufficient to properly identify bacteria?

a. Identification is only needed in clinical specimens.
b. Not all bacteria can be seen with a light microscope.
c. Many unrelated bacteria can share the same shape.
d. Bacteria have a limited set of shapes.
e. Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.

e. Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.

What is the hallmark of dichotomous keys?

a. They are open-ended questions.
b. They only relate to biochemical processes of the cell.
c. They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.
d. They only relate to the shape of the cell.

c. They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.

Biochemical tests _________________.

a. are the main methods used to identify unknown bacteria
b. are visualized using microscopes
c. are used to determine rate of growth
d. are the most effective way to determine bacterial shape

a. are the main methods used to identify unknown bacteria

How many answers are there to a question in a dichotomous key flowchart?

a. Two
b. Any number of answers are possible.
c. Four
d. Three

a. Two

Why are flowcharts useful for dichotomous keys?

a. They allow the researcher to visualize relationships between different bacteria.
b. They allow the researcher to get the answer without having to do many tests.
c. They provide a map to the answer.

a. They allow the researcher to visualize relationships between different bacteria.

The first question in this dichotomous key addresses

a. oxygen tolerance.
b. bacterial morphology.
c. metabolic characteristics.
d. Gram stain differences.

d. Gram stain differences.

Why is the unknown in this example not Pseudomonas?

a. It is a rod-shaped cell.
b. It can tolerate oxygen.
c. It ferments lactose.
d. It is a Gram-negative cell.

c. It ferments lactose.

What test result indicates that the unknown can utilize citrate as its sole carbon source?

a. The medium turns pink.
b. The culture becomes turbid.
c. It turns the medium black.
d. The medium turns blue.

d. The medium turns blue.

How would the results be different if this organism was Salmonella?

a. It would be a rod.
b. It would not ferment lactose.
c. It would produce hydrogen sulfide.
d. It would not tolerate oxygen.

c. It would produce hydrogen sulfide.

How is fermentation of lactose detected?

a. The medium become turbid when exposed to air.
b. The acetoin produced turns the medium pink.
c. The drop in pH turns the indicator dye yellow.
d. The cells form a black precipitant.

c. The drop in pH turns the indicator dye yellow.

How many questions are needed in this dichotomous key to determine if the unknown is Bacteroides?

a. Four
b. Three
c. Five
d. Two

b. Three

How are negative stains different from other types of stains?

a. They stain the desired structure or specimen black.
b. They stain more than one type of specimen.
c. They stain the background, leaving the cells colorless.

c. They stain the background, leaving the cells colorless.

Which of the following is an example of a dye used in a simple stain?

a. Methylene blue
b. Carbolfuchsin
c. Nigrosin
d. Eosin

a. Methylene blue

How does the malachite green stain enter an endospore?

a. It is mixed with hydrochloric acid.
b. It is dissolved in alcohol.
c. It is heated.
d. It is mixed with the mordant tannic acid.

c. It is heated.

Following an endospore stain, how does one distinguish endospores from vegetative cells?

a. Vegetative cells are pink, endospores are green.
b. Vegetative cells are pink, endospores are purple.
c. Vegetative cells are purple, endospores are pink.
d. Vegetative cells are green, endospores are pink.

a. Vegetative cells are pink, endospores are green.

What is the fundamental purpose of staining in light microscopy?

a. To kill the specimen
b. To make the specimen appear larger in the microscope
c. To see the specimen without the aid of a microscope
d. To increase the contrast and visibility of the specimen

d. To increase the contrast and visibility of the specimen

Which statement regarding viral species is true?

a. Viral species are not classified as part of any of the three domains.
b. Viral species are taxonomically differentiated based upon their cell wall.
c. Viral species are classified within the Kingdom Plantae in the Domain Eukarya.
d. Viruses are classified as prokaryotes.

a. Viral species are not classified as part of any of the three domains.

Numerical identification methods rely on a series of which kind of test to identify microorganisms?

a. ELISA
b. DNA base composition
c. DNA fingerprinting
d. biochemical testing

d. biochemical testing

Consider a gram-negative human pathogen isolated from marine mammals. This pathogen is subjected to a series of tests and found to have the following characteristics: oxidase-positive; does not hydrolyze urea; produces indole; does not produce acetoin. Which of the following could it be?

a. Pasteurella multocida
b. Mannheimia haemolytica
c. Klebsiella pneumoniae
d. Yersinia enterocolitica

a. Pasteurella multocida

Which technique is often used to determine the identity and abundance of microorganisms in an environment? (This technique is particularly useful because it does not require culture.)

a. nucleic acid hybridization
b. ribotyping
c. fluorescent in situ hybridization (FISH)
d. DNA chips

c. fluorescent in situ hybridization (FISH)

Which of the following techniques could be used to identify antibodies produced by a patient?

a. Southern blotting
b. FAME
c. FISH
d. Western blotting

d. Western blotting

Members of the Domain Archaea are characterized by all of the following except:

a. Carry out unusual metabolic processes
b. Contain distinctive ribosomal RNA
c. Contain nuclei
d. Live in extreme environments

c. Contain nuclei

A unicellular, photosynthetic nucleated cell would belong to Domain:

a. Archaea
b. Bacteria
c. Eukarya

c. Eukarya

The first cells were formed approximately ___________ years ago.

a. 3 million years ago
b. 3 billion years ago
c. 2 billion years ago

b. 3 billion years ago

If two organisms have similar rRNA sequences, you can conclude that

a. they evolved from a common ancestor.
b. they will have different G-C ratios.
c. they will both ferment lactose.
d. they live in the same place.
e. they mated with each other.

a. they evolved from a common ancestor.

Which of the following is the best evidence for a three-domain system?

a. There are three distinctly different types of nuclei.
b. There are three distinctly different sets of metabolic reactions.
c. Nucleotide sequences in ribosomal RNA vary between all three domains.
d. Some bacteria live in extreme environments.
e. There are three distinctly different Gram reactions.

c. Nucleotide sequences in ribosomal RNA vary between all three domains.

Biochemical tests are used to determine

a. staining characteristics.
b. nucleic acid-base composition.
c. enzymatic activities.
d. amino acid sequences.
e. All of the answers are correct.

c. enzymatic activities.

Which of the following is NOT based on nucleic-acid hybridization?

a. Western blotting
b. Southern blotting
c. DNA chip
d. PCR
e. FISH

a. Western blotting

The phylogenetic classification of bacteria is based on

a. gram reaction.
b. rRNA sequences.
c. cell morphology.
d. habitat.
e. diseases.

b. rRNA sequences.

Which of the following statements is a reason for NOT classifying viruses in one of three
domains rather than in a fourth domain?

a. Viruses direct anabolic pathways of host cells.
b. Viruses are obligate parasites.
c. Some viruses can incorporate their genome into a host's genome.
d. Viruses are not composed of cells.
e. All of the answers are correct.

d. Viruses are not composed of cells.

Bacteria and Archaea are similar in which of the following?

a. sensitivity to antibiotics
b. considered prokaryotic cells
c. methionine as the start signal for protein synthesis
d. peptidoglycan cell walls
e. plasma membrane ester linkage

b. considered prokaryotic cells

Serological testing is based on the fact that

a. antibodies react specifically with an antigen.
b. bacteria clump together when mixed with any antibodies.
c. all bacteria have the same antigens.
d. the human body makes antibodies against bacteria.
e. antibodies cause the formation of antigens.

a. antibodies react specifically with an antigen.

Nucleic acid hybridization is based on the fact that

a. DNA is composed of genes.
b. the strands of DNA can be separated.
c. pairing between complementary bases occurs.
d. all cells have DNA.
e. a chromosome is composed of complementary strands.

c. pairing between complementary bases occurs.

Which of the following criteria is most useful in determining whether two organisms are related?

a. Both are aerobic.
b. Both are motile.
c. Both are gram-positive.
d. Both ferment lactose.
e. Each answer is equally important.

c. Both are gram-positive.

You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in the group

a. Animalia.
b. Bacteria.
c. Plantae.
d. Archaea.
e. Fungi.

d. Archaea.

Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall?

a. Animalia
b. Fungi
c. Bacteria
d. Plantae
e. Protist

c. Bacteria

Which of the following characteristics indicates that two organisms are closely related?

a. Both of their DNA can hybridize.
b. Both are motile.
c. Both normally live in clams.
d. Both ferment lactose.
e. Both are cocci.

a. Both of their DNA can hybridize.

For which of the following would growth on blood agar be a good diagnostic tool?

a. streptococci
b. staphylococci
c. all Gram-positive cocci
d. enterococci

a. streptococci

Which of the following characteristics are shared by Enterococcus and Streptococcus?

a. found on/in healthy carriers
b. growth patterns on blood agar
c. cell arrangement
d. none of the above

c. cell arrangement

Which of the following techniques would allow you to easily differentiate between Staphylococcus and Enterococcus?

a. Gram stain
b. genetic testing
c. simple stain
d. all of the above

d. all of the above

Gram-positive organisms with low G + C content are commonly called __________.

a. proteobacteria
b. mycobacteria
c. Spirochaetes
d. Firmicutes

d. Firmicutes

Which gammaproteobacteria are facultatively anaerobic, gram-negative rods that inhabit the intestinal tracts of humans and other animals?

a. Pseudomonadales
b. Vibrionales
c. Enterobacteriales
d. Legionellales

c. Enterobacteriales

If a patient is diagnosed with a peptic ulcer, which genus of Proteobacteria is probably responsible?

a. Desulfovibrio
b. Campylobacter
c. Myxococcus
d. Helicobacter

d. Helicobacter

If a typhoid fever outbreak has occurred, which of the following statements is true?

a. Proteus colonies of Enterobacteriales are probably present.
b. Shigella species are present and may have been transmitted by cattle.
c. Salmonella is present, and the serovars may be differentiated by antigenic analysis.
d. Escherichia coli bacteria are present, probably passed on by infected human waste in the water supply.

c. Salmonella is present, and the serovars may be differentiated by antigenic analysis.

Regarding the order Rhizobiales of the class Alphaproteobacteria, which genus includes human pathogens?

a. Agrobacterium
b. Bradyrhizobium
c. Beijerinckia
d. Brucella

d. Brucella

You have isolated a gram-positive bacterium with low G + C content. It was a contaminant in unpasteurized milk. It infected a pregnant woman, and now you are worried that her child will be stillborn. What bacterium is it?

a. Anabaena
b. Listeria monocytogenes
c. Clostridium
d. Mycobacterium

b. Listeria monocytogenes

Which order or genus of Archaea are part of the microbiota of the human colon, vagina, and mouth?

a. Sulfolobales
b. Methanobacteriales
c. Halobacteriales
d. Pyrodictium

b. Methanobacteriales

Blood agar would be the culture medium of choice if one were testing a patient for which of the following?

a. tuberculosis
b. actinomycosis
c. scarlet fever
d. food poisoning

c. scarlet fever

Burkholderia was reclassified from the gammaproteobacteria to the betaproteobacteria because

a. it causes infections in cystic fibrosis patients.
b. it causes melioidosis.
c. it is a gram-negative rod.
d. it grows in disinfectants.
e. its rRNA sequence is similar to that of Neisseria.

e. its rRNA sequence is similar to that of Neisseria.

Thiobacillus oxidizes inorganic sulfur compounds and reduces CO2. This bacterium is a

a. chemoautotroph.
b. chemoheterotroph.
c. photoautotroph.
d. gammaproteobacteria.
e. photoheterotroph.

a. chemoautotroph.

Salmonella, Shigella, Yersinia, and Serratia are all

a. endospore-forming bacteria.
b. gram-negative facultatively anaerobic rods.
c. gram-positive aerobic cocci.
d. pathogens.
e. fermentative.

b. gram-negative facultatively anaerobic rods.

Which of the following statements about the causative agent of Rocky Mountain spotted fever is FALSE?

a. It is gram-negative.
b. It is found in soil and water.
c. It is an intracellular parasite.
d. It is in the genus Rickettsia.
e. It is transmitted by ticks.

b. It is found in soil and water.

Escherichia coli belongs to the

a. spirochetes.
b. proteobacteria.
c. green sulfur bacteria.
d. gram-positive bacteria.
e. actinomycetes.

b. proteobacteria.

You have isolated a bacterium that grows in a medium containing only inorganic nutrients. Ammonia is oxidized to a nitrate ion. This bacterium is

a. using anaerobic respiration.
b. a chemoautotroph.
c. a photoheterotroph.
d. gram-negative.
e. a photoautotroph

b. a chemoautotroph.

Requirements for X and V factors are used to identify

a. Pseudomonas.
b. Escherichia.
c. Neisseria.
d. Staphylococcus.
e. Haemophilus.

e. Haemophilus.

Rickettsias differ from chlamydias in that rickettsias

a. are enterics.
b. require an arthropod for transmission.
c. are intracellular parasites.
d. form elementary bodies.
e. are gram-negative.

b. require an arthropod for transmission.

Which of the following is NOT an enteric?

a. Enterobacter
b. Campylobacter
c. Shigella
d. Escherichia
e. Salmonella

b. Campylobacter

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