Micro Tophat module 3

An M-trophic HIV could infect A Only macrophages expressing CD4 B Only macrophages expressing CD4 and CCR5 C Only macrophages expressing CD4, CCR5 AND CXCR4 D Only T cells expressing CD4 E Only T cells expressing CD4 and CCR5 F Only T cells expressing CD4, CCR5, and CXCR4 G Any cell expressing CD4 and CCR5 H Any cell expressing CD4 I Any cell expressing CD4 and CXCR4

g

A class II virus would A Use the host cell DNA dependent DNA polymerase to replicate it's genome B Use the host cell DNA dependent RNA polymerase to replicate it's genome C Use it's own DNA dependent DNA polymerase to replicate it's genome D Use it's own DNA dependent RNA polymerase to replicate it's genome E Use it's own RNA dependent RNA polymerase to replicate it's genome

A

A mutation disables the Cro protein what would be the effect? A The virus would be unable to repress CI which would lead the virus to enter the lysogenic phase B The virus would enter the lytic cycle C The virus would be unable to make a capsid D The virus would not be able to recognize any receptor

A

If the human influenza virus targets cells of the upper respiratory tract due to recognition of specific receptors found only on the lung, this is called A tissue tropism B host tropism C capsid tropism D binding tropism E species tropism

A

The director of a laboratory in charge of making the flu vaccine for the upcoming season is planning her production strategy. She must consider the phenomenon of reassortment, in which A two different viruses contribute genome segments to a reassorted genome that remains segmented. B two different viruses contribute genetic material to form a recombinant molecule. C genes within a genomic segment of a virus undergo a fast mutation rate in the presence of another virus. D there is antigenetic shift. E there is antigenetic drift.

A

How are enveloped viruses able to enter cells? Select all that apply Multiple answers:You can select more than one option A Fusion B Endocytosis C Diffusion D Active Transport

A, B

Which statements are not true of viral replication? Choose all that apply Multiple answers:You can select more than one option A A lysogenic cycle kills the host cell. B There are seven basic steps in the viral replication cycle. C Viral replication affects host cell function. D Newly released virions cannot immediately infect other cells. They must continue maturation.

A, B, D

Which viral classes would be affected if the host DNA polymerase was inhibited? Multiple answers:You can select more than one option A Class I B Class II C Class III D Class IV E Class V F Class VI

A, B, F

A class III virus would replicate it's genome in the host's A Nucleus B Cytoplasm C It could replicate in either the nucleus or the cyotplasm

B

Bob wants to be the stem cell donor for the next HIV stem cell transplant. Bob has a CCR5 delta 32 mutation, but only on one allele. Your HIV patient is ready for her stem cell transplant and you want to try to make her the third patient to be cured of HIV. Should you Bob's stem cells? A Yes. Bob's stem cells could prevent HIV infection in your patient B No. Bob's stem cells will likely NOT prevent HIV infection in your patient C There is no way to determine if Bob's stem cells will or will not prevent HIV infection

B

M trophic HIV A Commonly form syncytia B Do not form syncytia C May or many not form syncytia depending on the host environment

B

What is the receptor that phage lambda binds to in order to infect E.coli cells? A LPS molecules B The maltose porin C Glucose D The starch utilization system

B

Which of the following describe the constantly mutating influenza strains? A Antigenic shift B Antigenic drift C Both A and B D None of the above

B

Which of the following is false regarding Influenza replication and reassortment? A It has a segmented genome, consisting of 8 segments of (-) RNA B Reassortment can produce novel flu strains that can infect new or more organisms, which is a phenomenon called genetic drift C Many flu outbreaks have been characterized by mutations or reassortment in the HA and NA genes (H1N1, H3N2, etc. ) D After reassortment occurs between two flu strains infected the same host cell, the recombined flu viruses leave with a segmented genome consisting of 8 separate pieces

B

Which of the following is false regarding the lysogenic cycle? A The lysogenic cycle is done by temperate bacteriophages B The bacteriophage rapidly replicates its genome to lyse the host cell during lysogeny C temperate phages replicate via the lytic cycle D the temperate bacteriophage can acquire new genes from the host cell

B

Which statement is true of viral replication? Choose all that apply. Multiple answers:You can select more than one option A During a lytic cycle the host cell survives. B During attachment the virus attaches to specific receptors on the cell surface. C The viral capsid helps the host cell produce more copies of the viral genome. D mRNA works outside of the host cell to produce enzymes and proteins. E During a lysogeny the virus is actively making copies of itself F The viral cytoplasm contains the enzymes necessary for protein synthesis

B

Which statement is true? A A virion contains DNA and RNA. B Temperate phages can be both lytic and lysogenic C Viruses replicate outside of the cell. D Most viruses are large enough to be visualized with a light microscope. E Damage to the host DNA generally results in phages remaining in lysogeny

B

You have a patient homozygous for the CCR5 delta 32 mutation. No other mutations are noted in the patient.He is displaying signs and symptoms of an HIV infection. You test his blood and he is positive for HIV. What would you expect to find? A M trophic HIV B T trophic HIV C Both M trophic and T trophic HIV D Neither M trophic or T trophic HIV; your blood test must have been contaminated as the patient is resistant to HIV

B

Immediately after entering the cell how many lipid bilayers will surround the influenza capsid? A 4 B 2 C 5 D 6

B (endosome and envelope)

Which of the following steps is NOT part of the life cycle of a lytic phage? A Phage DNA is injected into the bacterial cell. B The phage DNA integrates into the bacterial chromosome. C Many copies of phage DNA are made. D The phage DNA is transcribed, and the resulting mRNA is translated to make capsid proteins. E All of the steps listed are part of the life cycle of a lytic phage.

B (lysogenic phase)

select all of the following that are true regarding the influenza virus Multiple answers:You can select more than one option A It is a Baltimore class III virus so it has a (-) sense RNA genome B It has HA proteins on its surface which help the virus enter a host cell C It enters via sialic-acid receptor mediated endocytosis D It is a Baltimore class V virus so it encodes and carries its polymerase E it has a single circular genome similar to bacteria

B, C, D

What are the components common to all virions? Choose all that apply. Multiple answers:You can select more than one option A DNA and RNA genomes B DNA or RNA genomes C Capsid D Envelope E Spike proteins F Ribosomes G Cytoplasm H Sigma factors

B, C, E

Which statement is true of reverse transcriptase? Choose all that apply. Multiple answers:You can select more than one option A It acts as a DNA dependent RNA polymerase. B It is encoded by retroviruses C It is carried by retroviruses D It acts as an RNA dependent RNA polymerase E It acts as an RNA dependent DNA polymerase F It acts as a DNA dependent DNA polymerase

B, C, E, F

If there was a mutation that deleted the M2 ion channel protein of the influenza virus how would this effect the viruses ability to infect human heart cells? (Assume heart cells do not have sialic acids) A It would not allow the influenza virus to exit the lysosome in the heart cells B It would cause the replication machinery used by the virus to not function in the heart cells C It would not effect influenza's infectivity of heart cells since the virus would not be able to enter the cells in the first place. D The M2 ion channel does not exist in the influenza genome so it would have no effect.

C

Some viral species may derive their ____ from intracellular membranes, such as the nuclear membrane or endoplasmic reticulum. A Capsid B Genome C Envelope D Spike proteins E Tail Fibers

C

The correct sequence of events in viral multiplication is A Penetration, uncoating, synthesis, adsorption, assembly, release B Uncoating, penetration, synthesis, assembly, absorption, release C Adsorption, penetration, uncoating, synthesis, assembly, release D Assembly, synthesis, uncoating, release, penetration, adsorption E Adsorption, release, synthesis, uncoating, assembly, penetration F Adsorption, uncoating, penetration, synthesis, assembly, release

C

What type of diseases are unique in that they can be transmitted by an infective protein that propagates conformational change of existing molecules without synthesizing entirely new infective molecules? A Viroid B Virion C Prion D Defective viruses

C

Which class(es) of viruses MUST carry their own polymerase? A Class I & Class VI B Class IV & Class VI C Class V & Class VI D Class III and Class V E Class III and Class VI

C

Which of the following is correct about PrPc? A Contains DNA B Are Beta pleated sheets C Involved in cell to cell communication in brain D Highly infectious (transferred from human to human by standard contact) E Converts normal proteins to infectious proteins

C

Which of the following statements is false? A In the lytic cycle, new phage are produced and released into the environment. B In the lysogenic cycle, phage DNA is incorporated into the host genome. C An environmental stressor can cause the phage to initiate the lysogenic cycle. D Cell lysis only occurs in the lytic cycle.

C

Which of the following methods can be used to destroy prions A Nucleases (DNAse/RNase) B UV irradiations C Standard autoclave methods D Bleach E None of the above

E

Choose all that are true regarding Baltimore Class V viruses. (Multiple answers possible) Multiple answers:You can select more than one option A Movement into the nucleus is necessary for most. B The DNA-dependent RNA polymerase is encoded and carried by the virus upon entry into the host. C The viruses make use of host ribosomes for translation. D Influenza and ebola are grouped into this class. E Most stain pink with the gram stain.

C, D

A lab is studying an enveloped, class III virus known to infect tissue in the lung by exploiting a receptor specific to the upper respiratory tract. Out of curiosity, the new undergrad inserts the genome of this virus directly into the cytoplasm of a liver cell. If viral replication successfully occurs, you would expect the resulting virions to (choose all that apply) Multiple answers:You can select more than one option A be capable of infecting liver cells B have an envelope resembling the plasma membrane of lung cells C have an envelope resembling the plasma membrane of liver cells D no longer need an envelope E be capable of infecting lung cells F be capable of infecting any cell type in the body

C, E

A bacteriophage can infect ________. A the lungs B viruses C prions D bacteria

D

Influenza shows cyclic appearance of extremely virulent strains that may cause widespread infection with high mortality, such as that of 1918, which infected 20% of the world's population and killed more people than World War I. What is this type of infection called A Mutagenic B Epidemic C Endemic D Pandemic E Outbreak

D

RNA synthesis of influenza virus is primed by 7-methylguanine fragments of host mRNA, obtained by A Endocytosis B Exocytosis C Budding D Cap snatching E Transcription F Translation G It is encoded in the viral genome

D

Suppose that you have discovered and isolated a new strain of influenza. After performing some tests, you discover that this strain is lacking Hemagglutin. If one were to be exposed to this strain, would Tamiflu be an affective treatment? A Yes, it will still be capable of preventing the influenza from leaving the cell B No, it will no longer be capable of preventing the influenza from leaving the cell C Yes, it will still be capable of preventing the influenza from entering the cell. D No, it will be unnecessary as this strain of influenza will not be capable of entering the cell.

D

The viral _ plays a role in attaching a virion to the host cell. A genetic material B proteins extending from the capsid C proteins extending from the membrane D both b and c

D

Timothy Ray Brown, the "Berlin patient" was cured of HIV through a stem cell transplant. Is he completely resistant to another HIV infection? A Yes. His cells don't express CD4 so HIV can not enter his cells B Yes. His cells don't express CCR5 so HIV can not enter his cells C No. His cells don't express CD4 but he can still be infected with HIV through CCR5 and CXCR4 D No. His cells don't express CCR5 but he can still be infected with HIV through CD4 and CXCR4 E No. His cells don't express CD4, CCR5 or CXCR4 but he can still be infected through other cell surface receptors on T cells

D

Viruses with _ sense RNA contain the correct message for translation, while viruses with _ sense RNA must first be converted into a correct message. A negative; negative B negative; positive C positive; positive D positive; negative

D

Which of the following group of viruses first has to copy its RNA to form mRNA? A Double stranded DNA viruses B All RNA viruses C Retroviruses D Negative strand RNA viruses E Positive strand RNA viruses

D

Which of the following statements about virus structure is true? A All viruses are encased in a viral membrane. B The capsomere is made up of small protein subunits called capsids. C DNA is the genetic material in all viruses. D The space between the capsid and the envelope of the virus contain tegument proteins.

D

A class IV virus would A Use the host cell DNA dependent DNA polymerase to replicate it's genome B Use the host cell DNA dependent RNA polymerase to replicate it's genome C Use it's own DNA dependent DNA polymerase to replicate it's genome D Use it's own DNA dependent RNA polymerase to replicate it's genome E Use it's own RNA dependent RNA polymerase to replicate it's genome

E

The genome of HIV is A a double stranded RNA B a double stranded DNA C two identical plus sense RNAs D two identical minus sense RNAs E two plus sense RNAs that code for the same genes but are not identical F two minus sense RNAs that code for the same genes but are not identical

E