Microbiology - Chapter 4: Viruses

Which of the following is true about an antigenic shift? A. It avoids genetic reassortment. B. It causes major changes in the flu virus. C. All of the answers are correct. D. It causes minor changes in the flu virus. E. It doesn't cause any changes in the flu virus.

B. It causes major changes in the flu virus.

Which of the following is true about antigenic drift? A. It causes major changes in the flu virus. B. It causes minor changes in the flu virus. C. It doesn't cause any changes in the flu virus. D. None of the answers are correct. E. It results in the genome reasserting.

B. It causes minor changes in the flu virus.

Which of the following is NOT true about reverse transcriptase? A. In RNA viruses it uses a DNA intermediate to make more RNA B. It does not enable HIV to infect the cells C. It can be found in DNA and RNA viruses D. It is a type of polymerase E. In DNA viruses it uses an RNA intermediate to make more DNA

B. It does not enable HIV to infect the cells

All of the following are reasons why the icosahedral shape is a common viral shape that affects animals EXCEPT: A. Lots of energy is conserved when using this structure B. The lipid portion of envelope the virus encodes for protects it from environmental damage C. Plenty of room inside for nucleic acid D. Identical protein subunits are used to build the shape E. Genetic economy occurs

B. The lipid portion of envelope the virus encodes for protects it from environmental damage

+ssRNA has the same sense as: A. DNA B. mRNA C. UNA D. dsRNA E. dsDNA

B. mRNA

A virus that infects a bacteria is known as a(n): Eukaryophage Virophage Bacteriovirus Prokayrophage Bacteriophage

Bacteriophage

A common debate in biology centers on whether or not viruses are living things. What is a plausible reason that they could be considered living? Because they breathe, like all living things. Because they utilize ATP and break down food, like other living things. Because they can exist in a dormant state. Because they grow, like other living things. Because they contain either DNA or RNA, which are only found in living things.

Because they contain either DNA or RNA, which are only found in living things.

RNA viruses replicate in the: Cytoplasm Mitochondrion Endoplasmic reticulum Ribosomes Nucleus

Cytoplasm

RdRp helps to create: A. dsDNA from dsRNA B. ssDNA from dsRNA C. dsRNA from ssDNA D. RNA from DNA E. A complementary strand of RNA

E. A complementary strand of RNA

After the bacteriophage uses its tail fibers to attach to the bacterial host, what will happen next in the lytic cycle? A. Integration of viral nucleic acid into the bacterial genome B. Assembly of the new viruses C. Lysis of the bacterial cell wall D. Degradation of host DNA E. Injection of viral DNA

E. Injection of viral DNA

Which of the following describes a process that involves viral integration into the host genome? A. Living B. Prophage C. Replication D. Lytic cycle E. Lysogenic cycle

E. Lysogenic cycle

Reverse transcriptase helps to convert: A. dsDNA into dsRNA B. dsRNA into ssDNA C. ssDNA into dsRNA D. dsRNA into dsDNA E. ssRNA into dsDNA

E. ssRNA into dsDNA

Which of the following is NOT a method of viral release? Dormancy Budding Apoptosis Injection Exocytosis

Injection

Which of the following methods is NOT a method of viral release? Exocytosis Budding Apoptosis Injection None of these are methods of viral release

Injection

Why is Smallpox is a notable exception to the general replication scheme of DNA viruses? It is a single-stranded DNA virus. It is a retrovirus It has prepackaged virally encoded enzymes and replicates in the cytoplasm It replicates only in the nucleus. None of the answers are correct

It has prepackaged virally encoded enzymes and replicates in the cytoplasm

What is the function of a viral envelope? It increases infectivity of the virus. It holds the nucleic acids inside the virus. It allows the host to recognise the virus. It helps the virus attach to the host. It replaces the capsid.

It increases infectivity of the virus.

Which of the following best describes a polymerase? It is an enzyme that blocks the formation of nucleic acids. It is an enzyme that slows the formation of DNA. It is an enzyme that catalyzes the formation of nucleic acids. It is a ribosome that catalyzes the formation of nucleic acids.

It is an enzyme that catalyzes the formation of nucleic acids.

At minimum, a virus, be it bacteriophage or otherwise, needs the following in order to survive and take over its host: Nucleic acid and protein capsid None of the answers are correct Nucleic acid and envelope Envelope and protein capsid Protein capsid and envelope

Nucleic acid and protein capsid

Which of the following are present in ALL virions? Ribosomes, nucleic acids, capsid, protomers DNA, capsomeres, capsid, protomers, envelope Capsomeres, nucleic acids, ribosomes, protomers, envelope Nucleic acids, capsomeres, capsid, protomers RNA, capsomeres, capsid, protomers, envelope

Nucleic acids, capsomeres, capsid, protomers

DNA viruses replicate in the: Mitochondrion Endoplasmic reticulum Cytoplasm Nucleus Ribosomes

Nucleus

Viruses can be classified based on their: Physical and chemical properties Method of entry Method of release Color None of the answers are correct

Physical and chemical properties

A variant of the icosahedral shape found in some bacteriophages is called: Complex Helical Prolate Nucleic Enveloped

Prolate

A virion consists of all but the following: Capsomeres Nucleic acids Ribosomes In some viruses a viral envelope Capsid

Ribosomes

Which of the following refers to the process by which viruses are expelled out of their host cell? Maturation Attachment Viral shedding The lytic cycle Lysogeny

Viral shedding

Which of the following refers to the process by which viruses are expelled out of their host cell? Maturation Viral shedding Attachment The lytic cycle Lysogeny

Viral shedding

The infective form of a virus existing outside of its host cell is known as a: Capsid Virion Bacteriophage Virioid None of the answers are correct

Virion

What are two of the most important surface proteins found on the influenza virus? A. Hemagglutinin and Neuraminidase B. CD4 and CD8 C. MHC and CD99 D. COX-1 and COX-2 E. LOX and Neuraminidase

A. Hemagglutinin and Neuraminidase

Which of the following could trigger the lytic cycle of a bacteriophage? A. Host cell stress B. Host cell replicating its genome C. Host cell dividing D. Bacterial protein synthesis

A. Host cell stress

Why is an antigenic shift in a virus so dangerous? A. It alters the virus in such a way that our immune system doesn't know how to combat it. B. It combines the deadliest features of another virus into its genetic makeup. C. The disease mutates into an entirely new form. D. It weakens our immune system.

A. It alters the virus in such a way that our immune system doesn't know how to combat it.

In regards to an enveloped virus, which is of these choices is true? A. It has a fatty, lipid bilayer, used to increase infectivity B. It does not have a capsid C. It is able to reproduce without infecting a host D. It has a capsid but it is composed of lipids as opposed to proteins E. It must be stamped prior to being sent via the Unites States Postal Service

A. It has a fatty, lipid bilayer, used to increase infectivity

How do you define a polymerase? A. It is an enzyme that catalyzes the formation of nucleic acids. B. It is an enzyme that slows the formation of DNA. C. It is an adhesion molecule. D. It is an enzyme that blocks the formation of nucleic acids. E. It is a ribosome that catalyzes the formation of nucleic acids.

A. It is an enzyme that catalyzes the formation of nucleic acids.

A process whereby two viruses mix and match parts of their genome is called _____. A. genetic reassortment B. genetic diversity C. point mutations D. antigenic drift E. genetic deviation

A. genetic reassortment

In general, DNA viruses that affect humans: Use the host cell's machinery to replicate Use the host's enzymes to replicate Replicate in the nucleus All of the answers are correct Are double-stranded

All of the answers are correct

Which of the following is the best definition of a virion? An infective virus inside of a host An infective virus outside of a host An inert virus inside of a host An inert virus outside of a host A virus which has infected a bacteria

An infective virus outside of a host

A viral shape that isn't classified as purely helical or icosahedral is referred to as: Capsid Simple Prolate Enveloped Complex

Complex

Which of the following can be used directly to code for important viral proteins during viral replication? A. -RNA B. dsDNA-RT C. +RNA D. ssDNA-RT E. dsRNA

C. +RNA

Which of the following is most likely to be responsible for a flu pandemic? A. A bacteria B. Antigenic drift C. Antigenic shift D. A point mutation E. None of the answers are correct.

C. Antigenic shift

Which of the following is NOT a characteristic of a virus? A. Containing nucleic acid B. Surrounded by capsid proteins C. Containing ribosomes for translation D. Nonliving

C. Containing ribosomes for translation

A latent infection: A. Never occurs B. Is the same thing as the latent period of an active infection C. Is when a virus lies dormant inside a cell and no viral progeny is produced D. Is akin to the attachment phase of replication E. Is something that occurs during the lytic cycle

C. Is when a virus lies dormant inside a cell and no viral progeny is produced

Which of the following is not a feature of reverse transcriptase? A. It can create double-stranded DNA from RNA. B. It causes the high mutation rate of HIV. C. It can incorporate DNA into the host cell's genome. D. It is very error-prone.

C. It can incorporate DNA into the host cell's genome.

Why does it matter that HIV is a provirus? A. Its genetic makeup is more complex than other viruses. B. It does not have to bind to living cells to survive. C. It can incorporate itself into the host cell's DNA and lay dormant for a long period. D. It is able to reproduce itself where other viruses are not.

C. It can incorporate itself into the host cell's DNA and lay dormant for a long period.

A temperate virus is one that will first: A. Avoid the lysogenic cycle B. Enter the lytic cycle C. Lie dormant or cause a latent infection as it enters the lysogenic cycle D. Cause apoptosis E. Immediately lyse the cell upon entry and replication

C. Lie dormant or cause a latent infection as it enters the lysogenic cycle

How do HIV and Influenza viruses differ? A. HIV does not require a living cell as a host in order to survive. B. Influenza changes using rapid mutation. C. They evade the immune system in different ways. D. They experience the effects of an antigenic shift in different ways.

C. They evade the immune system in different ways.

Translation is where: A. -ssRNA is used by ribosomes to produce a protein B. -dsRNA is used by ribosomes to produce a protein C. mRNA is used by ribosomes to produce a protein D. mDNA is used by ribosomes to produce a protein E. +dsRNA is used by ribosomes to produce a protein

C. mRNA is used by ribosomes to produce a protein

A viral capsid is composed of subunits called: Envelopes Nucleic Acids RNA Coats Capsomeres, which are in turn made of protomers

Capsomeres, which are in turn made of protomers

+ssRNA viruses: A. Are converted to DNA before replication B. Are converted into a dsRNA virus before replication C. Are unable to make proteins directly D. Do not need a prepackaged RdRp E. None of the answers are correct

D. Do not need a prepackaged RdRp

Which of the following describes a process that involves viral replications and assembly within a host, followed by bursting the host cell wall? A. Lysogenic cycle B. Prophage C. Replication D. Lytic cycle E. Living

D. Lytic cycle

What are antigenic shifts? A. Sudden, significant changes to a major antigen of a pathogen that make the pathogen easier for the immune system to recognize. B. When a pathogen moves the antigens around on its surface to disguise itself from the immune system. C. Gradual changes over time to a major antigen of a pathogen that occur through mutation. D. Sudden, significant changes to a major antigen of a pathogen that usually occur through reassortment and can cause a pandemic.

D. Sudden, significant changes to a major antigen of a pathogen that usually occur through reassortment and can cause a pandemic.

Viral nucleic acids that comprise a viral genome can be: UNA only RNA only DNA or RNA RNA or UNA DNA only

DNA or RNA

Which of the following methods is NOT a method of viral penetration? Injection Membrane fusion Endocytosis Exocytosis None of these are methods of penetration

Exocytosis

A filamentous or rod-shaped virus is also known as a: Prolate virus Complex virus Enveloped virus Helical virus Icosahedral virus

Helical virus

How can you explain that an adult who had chicken pox, is now at risk of the shingles infection if you know that both diseases are caused by the same virus? This is the same thing as the latent period of an active infection. This is akin to the attachment phase of replication. This is something that occurs during the lytic cycle. The virus has been lying dormant inside the cells for some time and can begin reproducing again later. This could never occur.

The virus has been lying dormant inside the cells for some time and can begin reproducing again later.

Why are scientists debating if viruses are living organisms? They infect other pathogens. They are so small. They are metabolically inert. They don't always have DNA. They live inside a host.

They are metabolically inert.

Which of the following statements about DNA viruses that affect humans is FALSE? They use the host's enzymes to replicate. They replicate in the nucleus. They are single-stranded. They use the host cell's internal machinery to replicate.

They are single-stranded.

Why are Ribosomes important in the replication of DNA Viruses? They produce dsDNA. They produce dsRNA. They make lipids. They synthesize carbohydrates. They produce proteins.

They produce proteins.

The process whereby DNA is converted into mRNA is known as: Transcription Latency Replication Translation Transliteration

Transcription

A virus with an icosahedral shape that has a surrounding lipid bilayer that facilitates infection is known as _____ virus. a prolate a complex an icosahedral a helical an enveloped

an enveloped