Mastering Micro HW questions (8-12)

In which direction does DNA polymerase synthesize the new DNA strand? -Both 5' to 3' and 3' to 5' -5' to 3' -3' to 5'

-5' to 3'

Based on the animation, what is transferred during bacterial conjugation? -A bacterial chromosome -A conjugation pilus -RNA -A bacterial plasmid

-A bacterial plasmid

The genetic code is degenerate. Which of the following answers describes an example of the degenerate nature of the code? -There are no pauses or commas in the code. -The sequence "AUGCCGAUU" is read as three codons, AUG, then CCG, then AUU. -AUU codes for Ile in a wide variety of species -AUU, AUC, and AUA all code for Ile

-AUU, AUC, and AUA all code for Ile

Plasmids are commonly used as cloning vectors because __________. -they replicate independently of the chromosome -they can contain genes for antibiotic resistance -they are easily inserted into cells by transformation -All of the listed responses are correct.

-All of the listed responses are correct.

When describing the viral genome, which terms could be used? -ss DNA -ds DNA -ds RNA -All of the listed responses are correct.

-All of the listed responses are correct.

Restriction endonucleases are found in nature. They are extremely useful for genetic engineering. Why do organisms produce them? -They are part of the viral life cycle and help in the assembly of new viruses. -Because they cut only at specific sequences in DNA, they are useful in cutting harmful DNA (such as viral DNA) without harming the organism that produces them (which can protect those sequences in its own DNA). -They are involved in DNA replication in prokaryotes. -Organisms produce them as a way of allowing new genetic material to be inserted.

-Because they cut only at specific sequences in DNA, they are useful in cutting harmful DNA (such as viral DNA) without harming the organism that produces them (which can protect those sequences in its own DNA).

Bacterial conjugation is often referred to as bacterial sex. Why is this term inaccurate? -Conjugation does not result in the formation of new offspring. -Sex is a phenomenon only seen in animals. -Bacteria are neither male nor female. -It does not require two cells to occur

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

Which statement about conjugation is false? -After conjugation, each cell involved has a copy of the shared DNA. -E. coli is the model for bacterial conjugation. -Conjugation is a process of bacterial reproduction.

-Conjugation is a process of bacterial reproduction.

Which of the following terms is used to describe a synthetic DNA fragment? -DNA hybrid -artificial chromosome -DNA cassette -recombinant DNA

-DNA cassette

Which of the following attaches the target gene to a desired location? -DNA ligase -Restriction enzymes -Plasmids -Chromosomal DNA

-DNA ligase

Electrophoresis can be used to separate molecules by size, shape, and charge. When DNA samples are run in an electrophoresis gel, the different bands produced generally represent fragments of different sizes. Why is the size of the fragment the most critical factor in determining how far it migrates on a gel when DNA fragments are compared? -A special type of gel is used for DNA electrophoresis to minimize the effects of charge. -The shape of the DNA fragments has an even greater effect on movement than size or charge, so charge is relatively unimportant. -DNA moves toward a positive charge due to the negative charge on its phosphate groups. The charge is consistent because all DNA nucleotides have a single phosphate group rather than having more diverse patterns of charges. Because the charge is relatively consistent, size is the most important factor determining how far fragments move. -The charge on DNA is so small that it has a minimal effect on movement in the gel.

-DNA moves toward a positive charge due to the negative charge on its phosphate groups. The charge is consistent because all DNA nucleotides have a single phosphate group rather than having more diverse patterns of charges. Because the charge is relatively consistent, size is the most important factor determining how far fragments move.

The hepadnavirus DNA polymerase acts as which of the following? -protein primer for synthesis of a strand of DNA -reverse transcriptase -DNA polymerase -DNA polymerase, reverse transcriptase, and protein primer for DNA synthesis

-DNA polymerase, reverse transcriptase, and protein primer for DNA synthesis

What provides the energy for DNA polymerization in a PCR reaction? -Template DNA -Deoxyribonucleoside triphosphates -DNA polymerase -Primers

-Deoxyribonucleoside triphosphates

Which of the following events might trigger induction of a temperate bacteriophage? -Normal cell division of an infected cell -Exposure to UV light -An infected cell entering the logarithmic phase of growth -Bacterial conjugation

-Exposure to UV light

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

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

Transformation is a useful technique for making genetically modified bacteria in the laboratory. There have been efforts to transform Archaea, but it has been more difficult than transforming Bacteria. One reason that it has been difficult is that Archaea lack a peptidoglycan cell wall. Why does that affect the ability of researchers to develop techniques to transform them? -Relatively few viruses have been identified that infect Archaea. -It is difficult to create auxotroph strains of Archaea. -Genes for resistance to penicillin and related antibiotics can't be used as selectable markers. -Many Archaea are extremophiles and require conditions that are difficult to create in the lab.

-Genes for resistance to penicillin and related antibiotics can't be used as selectable markers.

Which of the following is NOT a common step in creating a genomic library? -Transform the vectors into a host. -Hybridize DNA sequences to form inserts of a target size range. -Fragment DNA into small segments. -Ligate DNA into vectors.

-Hybridize DNA sequences to form inserts of a target size range.

Why would a recombinant DNA molecule be inserted into a host cell? -It can be copied, transcribed, and translated into a desired protein. -It can protect the recombinant DNA. -Plasmids cannot be isolated outside of a host cell. -Restriction enzymes can only be used inside of a cell.

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

Why is DNA polymerase from Thermus aquaticus ideal for PCR? -It does not require energy to polymerize DNA. -It does not require primers. -It can synthesize DNA 5' to 3' and 3' to 5'. -It can withstand the high temperatures associated with PCR

-It can withstand the high temperatures associated with PCR

What is the fate of the prophage during the lysogenic stage? -It is packaged into viral proteins and maintained until the host is exposed to an environmental stress. -It is degraded by the activity of host defense enzymes. -It is copied every time the host DNA replicates. -It is released from the cell by lysing the cell.

-It is copied every time the host DNA replicates.

Which of the following repair mechanism(s) does not involve DNA polymerase? -Light-repair mechanism -Excision-repair mechanism -Mismatch-repair mechanism

-Light-repair mechanism

Which of the following repair enzymes cannot repair thymine dimers? -Excision-repair enzymes -Light-repair enzymes -Mismatch-repair enzymes

-Mismatch-repair enzymes

How do normal prion proteins (PrP) differ from the infectious prion proteins? -Normal PrP are found on mammals; infectious PrP are found on reptiles. -Normal PrP lack nucleic acid; infectious PrP have nucleic acid. -Normal PrP are found in all mammals; infectious PrP are found in only cows. -Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.

-Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.

Explain why viroids can only infect and damage plant cells, but not animal cells. -The genome of plant cells is made of RNA while animal cells have a DNA genome. -Plant cells contain a RNA polymerase that can copy RNA can animal cells do not. -Animal cells contain RNA polymerase that can copy RNA and plant cells do not. -Although both types of cells contain RNA, viroids recognize a specific receptor on the surface of plant cells.

-Plant cells contain a RNA polymerase that can copy RNA can animal cells do not.

How does the number of infectious prions increase? -Prions reproduce by binary fission. -Prions reproduce by mitosis. -Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion. -Prions form multimers which can then form more single copies of the prion protein.

-Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion.

From which phrase is the term "prions" derived? -Protein infections -Protein infection of the nervous system -Proteinaceous infectious particles -Particles of infection

-Proteinaceous infectious particles

Which of the following groups contains some representatives with genomes that are so small that they may have as few as two genes? -eukaryotes -bacteria -DNA viruses -RNA viruses

-RNA viruses

Which finding is most surprising from Griffith's experiments? -S strains are able to escape phagocytosis. -R strain cells fail to produce a capsule. -S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains. -S strain cells kill the mice.

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

Some proteins overexpressed at high levels resulting in the formation of inclusion bodies can abolish the goal of producing large quantities of active protein. What could be done to minimize this issue? -Decrease the number of biobricks in the vector. -Simultaneously produce intracellular chaperonins. -Switch to an expression host with a larger intracellular volume. -Codon optimize the gene.

-Simultaneously produce intracellular chaperonins

Why is a special polymerase, such as Taq polymerase, required for PCR? -Taq polymerase can add DNA or RNA, allowing amplification of DNA or RNA. -Taq polymerase adds bases more rapidly than other polymerases, allowing very rapid amplification. -Taq polymerase can add complementary bases in an extremely accurate way, resulting in a very low error rate. -Taq polymerase is produced by an extremophile prokaryote and is able to work at relatively high temperatures.

-Taq polymerase is produced by an extremophile prokaryote and is able to work at relatively high temperatures.

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

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

Which statement describes the difference between the normal neuron protein PrPC and the pathogenic version PrPSc? -The PrPC protein contains more beta sheets while the PrPSc protein contains more alpha helices. -PrPC is just a protein and the PrPSc is a protein with nucleic acid inside. -The three-dimensional conformation is identical, but the amino acid sequence is different. -The amino acid sequence is identical, but the three-dimensional conformation is different.

-The amino acid sequence is identical, but the three-dimensional conformation is different.

What characteristic of the S strain allows it to evade the immune system of the mice? -They are resistant to heat. -They are genetically engineered to be resistant to killing. -They are naturally competent. -The cells have a capsule.

-The cells have a capsule.

What must occur for bacterial conjugation to take place? -One of the cells must be E. coli. -The cells must come into contact with each other. -Each cell must contain a plasmid. -The cells must transfer RNA.

-The cells must come into contact with each other.

During conjugation, if an Hfr cell is mated with an F- cell, why will the F- cell remain F-? -The cells would not stay in contact long enough for the entire Hfr genome to be transferred. -The donor cell is not an F+ cell, it is Hfr. -The recipient will not remain F-, it will become F+. -The recipient will not remain F-, it will become Hfr because of the donor cell genome.

-The cells would not stay in contact long enough for the entire Hfr genome to be transferred.

Which of the following would result in a frameshift mutation? -The addition of three nucleotides between two existing codon. -The deletion of two nucleotides in a codon -The deletion of three nucleotides in a codon -The deletion of one nucleotide from one codon and two nucleotides from the adjacent codon

-The deletion of two nucleotides in a codon

How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell? -The host cell is allowed to live during the lytic stage. -The viral DNA may integrate into the host genome during the lytic stage. -The host cell can only divide during the lytic stage. -The host cell dies during the lytic stage.

-The host cell dies during the lytic stage.

Why is light required for photolyases? -The light helps identify the damaged strands. -Light is used to activate the DNA polymerase to repair the gap. -Light excises the section of DNA to be repaired. -The light provides the energy to break the bonds between the thymine dimers.

-The light provides the energy to break the bonds between the thymine dimers.

How is DNA methylation used in DNA repair? -The mismatch-repair enzymes can use a lack of methylation to identify and remove newly synthesized DNA. -Methyl groups are required to cut DNA. -Methyl groups activate photolyases in light-repair. -Methyl groups identify thymine dimers in the DNA.

-The mismatch-repair enzymes can use a lack of methylation to identify and remove newly synthesized DNA.

A single base substitution happens to cause a nonsense mutation early in the gene for a protein. What will be the result? -The protein will be truncated a small amount, but is unlikely to function normally. -The protein will be truncated a small amount, but is likely to function normally. -The protein will be truncated so much that it is unlikely to function normally. -The protein will be truncated a great deal, but is likely to function normally.

-The protein will be truncated so much that it is unlikely to function normally.

How do restriction enzymes cut DNA sequences? -They cut DNA at sites, called recognition sites, that have specific nucleotide sequences. -They cut DNA at sequences that have lots of adenine bases. -They have the ability to cut DNA randomly.

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

In a culture of bacteria, there are some individuals that are unable to synthesize histidine. What is the best and most likely description of how these individuals differ from the other bacteria in the culture? -They differ in their genotype but not in their phenotype. -They don't differ in genotype or phenotype. -They differ in their phenotype but not in their genotype. -They differ in their genotype and in their phenotype.

-They differ in their genotype and in their phenotype.

What is the function of the primers in PCR? -They provide a 3' end for the DNA polymerase. -They are the monomer building blocks from which the DNA strand is synthesized. -They polymerize free nucleotides to form the new DNA strands. -They provide energy for the DNA polymerization reactions

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

In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene? -To remove an undesirable gene -To insert a desirable gene -To replace a defective gene with a working gene -To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene

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

What is unique about transduction compared to normal bacteriophage infection? -The bacteriophage takes fragments of the cell with it during transduction. -The bacteriophage does not erupt from an infected cell during transduction. -Transduction transfers DNA from the chromosome of one cell to another.

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

When bacterial recombination occurs through a virus, the process is called transduction. What is the name of the process when bacteria pick up naked DNA from the environment without the involvement of a virus? -Conjugation -Conjugation, transformation, or transduction are all possible ways that recombination could occur, allowing a bacterium to pick up naked DNA from the surrounding environment -Transduction -Transformation

-Transformation

Which of the following is NOT a way in which viruses are different from living organisms? -Viruses have DNA or RNA, not both -Viruses are acellular and all living things are made up of cells -Viruses are obligate parasites and no living organisms are obligate parasites. -Viruses depend on their host to synthesize the essential components of new viruses (e.g., genetic material and proteins), while living organisms are capable of synthesizing these components even if they require a host for food, shelter, or other necessities.

-Viruses are obligate parasites and no living organisms are obligate parasites.

Frameshift mutations can be very severe. What is one reason why they are often so serious? -When a frameshift mutation occurs, it causes transition mutations to occur. These are particularly severe. -When a frameshift mutation occurs, it causes changes in many bases downstream and can affect many of the amino acids in the protein. -Frameshift mutations always occur in the regulatory region, so they cause a gene to be turned off and then the protein is not produced at all. -When a frameshift mutation occurs, it causes changes in many bases upstream and can affect many of the amino acids in the protein

-When a frameshift mutation occurs, it causes changes in many bases downstream and can affect many of the amino acids in the protein.

Inserting a kanamycin resistance cassette into a catabolic operon to confirm the gene is essential in degradation of a particular compound would involve all of the following EXCEPT -ligation. -transformation. -recombination. -a reporter gene.

-a reporter gene.

Based on what is currently thought about lytic versus lysogenic life cycles, which of the following viruses would be most likely to be found as a prophage? -a virus that is found in a high-density population of host animals -a virus that is found in a high-density population of host bacteria deep in the ocean -a virus that is found in a low-density population of host bacteria deep in the ocean -a virus that is found in a moderate-density population of host bacteria

-a virus that is found in a low-density population of host bacteria deep in the ocean

An organism that cannot synthesize methionine is called __________. -a prototroph -a mutant -an auxotroph -an autotroph

-an auxotroph

The normal function of the PrP protein in mammals is believed to be: -assisting in normal membrane development and function. -assisting in normal synaptic development and function. -assisting proteins in forming beta-pleated sheets. -assisting proteins in forming alpha-helices.

-assisting in normal synaptic development and function.

Blocking polyomavirus SV40's ability to integrate its genome into host cells would -switch SV40 into a lytic lifecycle which would be especially harmful to the host cells. -increase the rate of transformation. -increase the latent period of SV40. -avoid cancer development from the virus.

-avoid cancer development from the virus.

Rolling circle replication of the lambda genome differs from replication of a bacterial chromosome in that -no concatamers are formed. -only a single strand of the genome is copied and no concatamers are formed. -only a single strand of the genome is copied. -bidirectional replication forks are not formed.

-bidirectional replication forks are not formed.

Which of the following are viable methods of release of newly assembled viral particles? -lysis of host cell -lysogeny -budding or lysis of host cell -budding

-budding or lysis of host cell

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

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

What are the minimal components needed for a virion? -capsid and genome -genome and envelope -capsid -capsid, genome, envelope

-capsid and genome

The cells used as hosts for cloning vectors are __________. -always eukaryotic -always E. coli -always prokaryotic -chosen based on correct cloning and gene expression

-chosen based on correct cloning and gene expression

Cellular receptors may be composed of -lipids. -proteins. -carbohydrates. -combinations of proteins, carbohydrates, and/or lipids.

-combinations of proteins, carbohydrates, and/or lipids.

A transducing phage -contains fragments of the host chromosome instead of the viral genome. -cannot infect new host cells. -is a lysogenic bacteriophage. -has a viral coat made of host proteins.

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

The virus repressor protein -controls both the lytic genes on the prophage and prevents an incoming virus of the same type. -has different actions in different situations. -does not control the prophage's lytic genes but does control the incoming genomes of the same virus. -controls the prophage's lytic genes but not the incoming genomes of the same virus

-controls both the lytic genes on the prophage and prevents an incoming virus of the same type.

Among the largest RNA genome viruses are ________ which contain a ________ genome. -polioviruses / dsRNA -coronaviruses / dsRNA -polioviruses / positive ssRNA -coronaviruses / positive ssRNA

-coronaviruses / positive ssRNA

Reoviruses contain ________ genomes, and their replication occurs within the host's ________. -dsDNA / nucleus -dsRNA / cytoplasm -ssRNA / cytoplasm ssDNA / nucleus

-dsRNA / cytoplasm

At which time period(s) during PCR thermocycling is/are hottest in temperature? -during DNA denaturation -during primer extension/elongation -during primer annealing -Both the first and last cycles are hotter in temperature than all other cycles

-during DNA denaturation

What molecular mechanism/feature does site-directed mutagenesis exploit to introduce a mutation at a specific site? -flanking complementary bound nucleotides permit non-complementary base pairing -methylated nucleotides disrupt DNA polymerase's proofreading -nucleotide substitution when one is depleted -transposase-induced base pair changes

-flanking complementary bound nucleotides permit non-complementary base pairing

A new chemotherapeutic agent is developed that alters the structure of all thymines in DNA. These thymines are then misread during the production of mRNA. Which of the following could NOT result from this type of mutation? -silent mutation -nonsense mutation -missense mutation -frameshift mutation

-frameshift mutation

A silent mutation is so named because __________. -it results from the deletion of DNA, thus silencing the gene -it causes a frameshift, thus altering protein structure -it has no effect on the overall amino acid sequence -it results in a premature termination of the amino acid sequence

-it has no effect on the overall amino acid sequence

Cloning vectors can be distinguished from expression vectors by -carrying ori genes for replication of the cloned sequence. -having a high copy number per cell. -having a multiple cloning site (MCS). -lacking a promoter site upstream of the insertion site.

-lacking a promoter site upstream of the insertion site.

In DNA cloning, fragments of DNA need to be joined together (e.g., to add a fragment into a vector). What common enzyme is used for this process? -helicases -DNA polymerase -ligase -RNA polymerase

-ligase

If a bacterium carrying a plasmid that confers resistance to ampicillin is placed into medium without ampicillin, it may -undergo a reversion mutation. -lose the plasmid because there is no selection for ampicillin resistance. -transfer resistance to other cultures in the laboratory. -gain resistance to other antibiotics.

-lose the plasmid because there is no selection for ampicillin resistance.

What makes eukaryotic transcripts easier to isolate than transcripts in bacteria? -Larger transcript size in eukaryotes enables easy size-selection methods. -Transcripts are the most abundant RNAs in eukaryotes. -Eukaryotic transcripts are not methylated but their genes are often methylated. -mRNA is polyadenylated in eukaryotes.

-mRNA is polyadenylated in eukaryotes.

A shuttle vector is most useful for -making a foreign protein in a mammalian cell. -engineering a complete metabolic pathway. -identifying the localization of a protein. -knocking out a gene by cassette displacement.

-making a foreign protein in a mammalian cell.

Viral structural proteins and proteins involved in the release of new viral particles that are synthesized after genomic replication begins would be considered -late proteins -middle proteins -early proteins -middle and late proteins

-middle and late proteins

Bacteriophage have a ________ complex structure than animal viruses, because ________. -more / the bacteriophage must penetrate the peptidoglycan cell wall -less / there prokaryotic cells have a simple structure compared to eukaryotic cells -less / the bacteriophage does not have to penetrate the nucleus -more / bacteriophages must be coated by lipopolysaccharide to attach to bacterial cells

-more / the bacteriophage must penetrate the peptidoglycan cell wall

In contrast to positive ssRNA viruses such as coronaviruses and polioviruses, the genome of retroviruses -is negative ssRNA. -lacks genes encoding for tRNA primers. -lacks ribonuclease activity. -must first integrate into the host's genome before transcription.

-must first integrate into the host's genome before transcription.

While studying protein synthesis in the lab, you experimentally induce a mutation in a bacterium's DNA. You assess the proteins in the mutated bacterium and find that one of them is significantly shorter than its wild-type counterpart. Based on this information, what type of mutation did you induce? -deletion mutation -nonsense mutation -silent mutation -missense mutation

-nonsense mutation

Viruses that contain an envelope and two identical copies of the RNA genome are called __________. -rhabdoviruses -reoviruses -retroviruses -herpesviruses

-retroviruses

The Baltimore Scheme to classify viruses contains a total of ________ groups based on ________. -seven / genome composition -seven / genome composition and transcription mechanism -four / genome composition and transcription mechanism -four / genome composition

-seven / genome composition and transcription mechanism

Mice that are injected with only the R strain of Streptococcus pneumoniae -are killed, because R strain cells are deadly. -stay healthy, because their immune systems can kill this strain easily. -become sick for prolonged periods of time.

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

When a transducing phage interacts with a new host cell, -the new host cell will be lysed. -it will cause the new cell to produce more transducing phage. -the DNA from the previous host can recombine with the new host chromosome.

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

In what year did Stanley Prusiner discover prions? 1982 1997 1979 1928

1982

High expression levels of a eukaryotic gene in a bacterium such as Escherichia coli cannot be accomplished due to the presence of introns. True False

FALSE

A bacteriophage that lacks its proteinaceous capsid structure is also called a viroid. True False

False

Viruses rely on the host cell machinery to make new viruses, but they sometimes provide their own enzymes (such as reverse transcriptase, which is an RNA-dependent DNA polymerase). Which of the following types of enzymes would a virus need to provide in order to replicate within a cell? In other words, which of these enzymes would not normally be found in a cell unless a virus provided it? -DNA-dependent RNA polymerases for DNA viruses -RNA replicases (RNA-dependent RNA polymerases) for RNA viruses -DNA-dependent DNA polymerases for DNA viruses -DNA-dependent RNA polymerases for RNA viruses

RNA replicases (RNA-dependent RNA polymerases) for RNA viruses

Which disease did Stanley Prusiner first identify as being caused by prions? -Scrapie -Fatal familial insomnia -Mad cow disease -Kuru

Scrapie

One fundamental technique of genetic engineering includes the ability to cut DNA into random fragments. True False

TRUE

Some virus shapes that infect members of Archaea are unique from other viruses that infect eukaryotes and bacteria. True False

TRUE

Why are the beta-pleated multimers of PrP potentially pathogenic? -They are found on the surface of immune cells, resulting in damage to the immune system. -They repress the immune system. -They are not detected by other organisms. -The multimers are more stable and resistant to protease.

The multimers are more stable and resistant to protease.

Genomics analysis of recently isolated viruses indicate some viruses contain larger genomes than the some bacterial genomes. True False

True

Most archaeal viruses identified appear to have DNA genomes. True False

True

A change in the base sequence of DNA that is passed on to daughter cells is __________. -lethal -a mistake -of no consequence -a mutation

a mutation

Lysogenic viral DNA integrating into the host genome is referred to as -lysogeny. -lytic. -induction. -a prophage.

a prophage

The unconventional dsDNA genome replication mechanism where no lagging strand exists is a hallmark of which group of viruses? -pox viruses -herpes viruses -coronaviruses -adenoviruses

adenoviruses

Which of the following are the hosts for most enveloped viruses? -Bacteria -Archaea -animals -fungi

animals

Because the influenza virus is segmented, when two different strains infect the same cell, a major change in the virus can occur that is called __________. -antigenic shift -hybridization -viral mutation -antigenic drift

antigenic shift

Viruses that infect the hyperthermophilic Archaea tend to contain genomes that are composed of -dsRNA. -ssRNA. -ssDNA. -dsDNA.

dsDNA

Sarah has cloned a gene that codes for the protein EN. EN breaks down cellulose. She wants to collect a large concentration of this protein for research. Which vector should she choose for best results? -plasmid -shuttle vector -expression vector -bacteriophage

expression vector

How are prions different from other infectious agents? -They cause neurological disease. -They lack protein. -They cannot replicate. -They lack nucleic acid.

lack nucleic acid

What type of vector can replicate and be maintained stably in two (or more) unrelated host organisms? expression shuttle virus integrating

shuttle

Increasing genetic variability by the uptake of DNA from the environment is __________. -transformation -a mutation -transduction -conjugation

transformation