Which of the following represents the use of osmotic pressure as a microbial control method?

Which of the following represents the use of osmotic pressure as a microbial control method?

A. bleaching a kitchen counter
B. salting meat
C. rinsing a cut with Betadine
D. Both bleaching a kitchen counter and rinsing a cut with Betadine are correct.

Answer: B

Antimicrobial agents can target the cell wall by

Antimicrobial agents can target the cell wall by

A. blocking its synthesis.
B. digesting it.
C. inhibiting peptidoglycan synthesis.
D. All of the choices are correct.

Answer: D

In lab, inoculating loops are sterilized using

In lab, inoculating loops are sterilized using

A. moist heat.
B. chemicals.
C. incineration.
D. filtration.
E. ethylene oxide.

Answer: C

Which of the following acids is not used to destroy or inhibit microbial cells in food?

Which of the following acids is not used to destroy or inhibit microbial cells in food?

A. acetic acid
B. benzoic acid
C. lactic acid
D. phosphoric acid
E. propionic acid

Answer: D

Ethylene oxide is

Ethylene oxide is

A. sporicidal.
B. only effective with high heat.
C. the active agent in household bleach.
D. used as an antiseptic against anaerobes.
E. a halogen.

Answer: A

Which of the following is not used as an antiseptic?

Which of the following is not used as an antiseptic?

A. iodophor
B. chlorhexidine
C. 3% hydrogen peroxide
D. betadine (povidone-iodine)
E. glutaraldehyde

Answer: E

Heavy metals work by

Heavy metals work by

A. rupturing the cell membrane.
B. inactivating proteins.
C. binding to DNA.
D. dissolving the cell wall.
E. mutating DNA.

Answer: B

All of the following disrupt the cytoplasmic membrane except

All of the following disrupt the cytoplasmic membrane except

A. detergents.
B. quaternary ammonium compounds.
C. high concentration phenols.
D. iodine.

Answer: D

Hydrogen peroxide can be

Hydrogen peroxide can be

A. sporicidal.
B. fungicidal.
C. bactericidal.
D. virucidal.
E. All of the choices are correct.

Answer: E

The chemical agent that produces highly toxic and reactive free radicals is

The chemical agent that produces highly toxic and reactive free radicals is

A. cidex.
B. cationic detergents.
C. hydrogen peroxide.
D. chlorhexidine.
E. iodophors.

Answer: C

Alcohols

Alcohols

A. dissolve membrane lipids at concentrations of greater than 50%.
B. can be used for disinfection or antisepsis.
C. are skin degerming agents.
D. are limited in effectiveness due to rapid evaporation.
E. All of the choices are correct.

Answer: E

The compound that is an organic base containing chlorine and two phenolic rings, and is used increasingly for mucous membrane irrigation, obstetrical washes, hand scrubbing, and prepping surgical skin sites is

The compound that is an organic base containing chlorine and two phenolic rings, and is used increasingly for mucous membrane irrigation, obstetrical washes, hand scrubbing, and prepping surgical skin sites is

A. carbolic acid.
B. chlorhexidine.
C. triclosan.
D. formalin.
E. quaternary ammonium compounds.

Answer: B

____ is a halogen used in gaseous and liquid form for large-scale disinfection of drinking water and sewage.

____ is a halogen used in gaseous and liquid form for large-scale disinfection of drinking water and sewage.

A. Iodine
B. Chlorine
C. Bromine
D. Fluorine
E. All of the choices are correct.

Answer: B

All of the following pertain to hypochlorites except

All of the following pertain to hypochlorites except

A. release hypochlorous acid in solution.
B. cause denaturation of enzymes.
C. found in iodophors.
D. used to disinfect water, restaurant, and medical equipment.
E. found in common household bleach.

Answer: C

Which of the following is not a factor that affects germicidal activity?

Which of the following is not a factor that affects germicidal activity?

A. the material being treated
B. the length of exposure
C. the strength of the germicide
D. the microorganism being treated
E. All of these are factors.

Answer: E

_____ is a control method that removes microorganisms rather than inhibiting or killing them.

_____ is a control method that removes microorganisms rather than inhibiting or killing them.

A. Boiling
B. Sterilization
C. Radiation
D. Filtration
E. Disinfection

Answer: D

Filtration can result in sterilization of serum and blood products

Filtration can result in sterilization of serum and blood products

A. by removing viruses.
B. by relying on gravity.
C. by removing toxins.
D. using high heat and filtration.
E. All of the choices are correct.

Answer: A

HEPA filters are used to remove microbes from

HEPA filters are used to remove microbes from

A. air.
B. liquids.
C. human tissues.
D. medical instruments.
E. All of the choices are correct.

Answer: A

Which of the following forms of radiation is in order from the most penetrating to the least penetrating?

Which of the following forms of radiation is in order from the most penetrating to the least penetrating?

A. gamma, cathode, X rays
B. gamma, X rays, cathode
C. cathode, gamma, X ray
D. cathode, X ray, gamma
E. X ray, gamma, cathode

Answer: B

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

A. ultraviolet (germicidal) light
B. gamma rays
C. 121C at 15 psi for 15 minutes
D. 160C for 2 hours
E. All of the choices are correct.

Answer: A

Which of the following items are typically irradiated in order to kill microbes?

Which of the following items are typically irradiated in order to kill microbes?

A. meats like ground beef and pork
B. human tissues such as heart valves and skin
C. operating room air
D. surgical gloves
E. All of the choices are correct.

Answer: E

_____ radiation excites atoms to a higher energy state within molecules such as DNA that then leads to the formation of pyrimidine dimers.

_____ radiation excites atoms to a higher energy state within molecules such as DNA that then leads to the formation of pyrimidine dimers.

A. Infrared
B. Ultraviolet
C. Gamma
D. Particle
E. Ionizing

Answer: B

Removal of moisture by dehydration is called

Removal of moisture by dehydration is called

A. desiccation.
B. flash freeze.
C. lyophilization.
D. pasteurization.
E. sterilization.

Answer: A

Vials of microorganisms that undergo the freeze-drying process called _____ will remain preserved and viable for years.

Vials of microorganisms that undergo the freeze-drying process called _____ will remain preserved and viable for years.

A. desiccation
B. flash freeze
C. lyophilization
D. pasteurization
E. sterilization

Answer: C

What instrument is most effective for pressure-temperature sterilization?

What instrument is most effective for pressure-temperature sterilization?

A. oven
B. autoclave
C. water bath
D. Bunsen burner
E. incubator

Answer: B

A method for sterilizing milk, called _____ treatment, uses 134C for 1 to 2 seconds.

A method for sterilizing milk, called _____ treatment, uses 134C for 1 to 2 seconds.

A. pasteurization
B. batch pasteurization
C. flash pasteurization
D. ultra high temperature
E. None of the choices is correct.

Answer: D

_____ heat is more rapidly effective and efficient compared to _____ heat.

_____ heat is more rapidly effective and efficient compared to _____ heat.

A. High, dry
B. High, moist
C. Dry, moist
D. Moist, dry
E. Moist, high

Answer: D

Pasteurization

Pasteurization

A. kills all vegetative forms.
B. reduces the number of vegetative forms.
C. reduces the number of endospores.
D. increases food nutrient value.
E. None of the choices is correct.

Answer: B

Placing organisms at 4 C is

Placing organisms at 4 C is

A. bactericidal.
B. bacteriostatic.
C. decontamination.
D. sterilization.
E. None of the choices is correct.

Answer: B

Disinfection of beverages such as apple juice, milk, wine is optimally achieved by

Disinfection of beverages such as apple juice, milk, wine is optimally achieved by

A. pasteurization.
B. chlorination.
C. moist heat autoclave.
D. filtration.
E. boiling water.

Answer: A

The lowest temperature needed to kill all microbes in 10 minutes is the

The lowest temperature needed to kill all microbes in 10 minutes is the

A. thermal death point (TDP).
B. thermal death time (TDT).
C. sporicidal time.
D. death phase point.
E. None of the choices is correct.

Answer: A

The shortest time required to kill all the microbes in a sample at a specified temperature is called the

The shortest time required to kill all the microbes in a sample at a specified temperature is called the

A. thermal death point (TDP).
B. thermal death time (TDT).
C. sporicidal time.
D. death phase point.
E. None of the choices is correct.

Answer: B

The most efficient sterilizing conditions in a steam autoclave are

The most efficient sterilizing conditions in a steam autoclave are

A. 121C at 15 psi for 15 minutes.
B. 63C for 30 minutes.
C. 160C for 2 hours.
D. 71.6C for 15 seconds.
E. 100C for 30 minutes.

Answer: A

Dry heat

Dry heat

A. is less efficient than moist heat.
B. cannot sterilize.
C. includes tyndallization.
D. is used in devices called autoclaves.
E. will sterilize at 121C for 15 minutes.

Answer: A

Sterilization is achieved by

Sterilization is achieved by

A. flash pasteurization.
B. hot water.
C. boiling water.
D. steam autoclave.
E. All of the choices are correct.

Answer: D

Physical agents for controlling microbial growth include all the following except

Physical agents for controlling microbial growth include all the following except

A. ultraviolet radiation.
B. boiling water.
C. HEPA filters.
D. pasteurization.
E. hydrogen peroxide.

Answer: E

Which of the following does not affect microbial nucleic acids?

Which of the following does not affect microbial nucleic acids?

A. moist heat
B. ultraviolet light
C. X rays
D. ethylene dioxide
E. formaldehyde

Answer: A

Agents that can denature microbial proteins include all of the following except

Agents that can denature microbial proteins include all of the following except

A. moist heat.
B. alcohol.
C. acids.
D. metallic ions.
E. X rays.

Answer: E

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state (three-dimensional configuration) of the proteins.

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state (three-dimensional configuration) of the proteins.

A. denature
B. bind
C. dissolve
D. activate
E. All of the choices are correct.

Answer: A

Surfactants work by

Surfactants work by

A. coating the organism, preventing interaction with its environment.
B. blocking transport into the organism.
C. blocking transport out from the organism.
D. disrupting membrane integrity.
E. All of the choices are correct.

Answer: D

Each of the following is the target of antimicrobial agents except

Each of the following is the target of antimicrobial agents except

A. cell walls.
B. cell membranes.
C. ribosomes.
D. cellular proteins.
E. cytoplasm.

Answer: E

Microbial death occurs when there is

Microbial death occurs when there is

A. no movement.
B. permanent loss of reproduction.
C. a change in appearance.
D. a decrease in size.
E. All of these occur.

Answer: B

Which of the following factors will influence the action of microbial agents?

Which of the following factors will influence the action of microbial agents?

A. the number of microorganisms
B. the kind of microorganisms
C. temperature and pH
D. mode and dosage of the agent
E. All of these will influence the action.

Answer: E

Which is correct regarding the rate of microbial death?

Which is correct regarding the rate of microbial death?

A. Cells die at increasingly greater rates.
B. Only older cells die in a culture.
C. Cells in a culture die at a constant rate.
D. Upon contact with the control agent, all cells die at one time.
E. Cells become metabolically inactive, but are never killed.

Answer: C

A cleansing method that mechanically removes microbes and other debris to reduce contamination is

A cleansing method that mechanically removes microbes and other debris to reduce contamination is

A. disinfection.
B. sterilization.
C. antisepsis.
D. sanitization.
E. degermation.

Answer: D

The alcohol wipe before an injection is an example of

The alcohol wipe before an injection is an example of

A. antisepsis.
B. disinfection.
C. sterilization.
D. decontamination.
E. virilization.

Answer: A

The betadine swab before blood donation is an example of

The betadine swab before blood donation is an example of

A. antisepsis.
B. disinfection.
C. sterilization.
D. decontamination.
E. sanitation.

Answer: A

The removal of all life forms from inanimate objects is termed

The removal of all life forms from inanimate objects is termed

A. antisepsis.
B. disinfection.
C. sterilization.
D. decontamination.
E. degerming.




Answer: C

The method of removing vegetative life forms from living surfaces is termed

The method of removing vegetative life forms from living surfaces is termed

A. antisepsis.
B. disinfection.
C. sterilization.
D. decontamination.
E. fegerming.

Answer: A

The method of removing vegetative microbial life forms from inanimate objects is termed

The method of removing vegetative microbial life forms from inanimate objects is termed

A. antisepsis.
B. disinfection.
C. sterilization.
D. decontamination.
E. degerming.

Answer: B

The easiest microbial forms to kill or inhibit are

The easiest microbial forms to kill or inhibit are

A. prions.
B. vegetative bacteria and fungi.
C. endospores.
D. protozoan cysts.
E. mycobacteria and staphylococci.

Answer: B

Which of the following types of control agents would be used to achieve sterility?

Which of the following types of control agents would be used to achieve sterility?

A. virucide
B. bactericide
C. germicide
D. sporicide
E. fungicide

Answer: D

Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is

Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is

A. disinfection.
B. sterilization.
C. antisepsis.
D. sanitization.
E. ionization.

Answer: C

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is

A. disinfection.
B. sterilization.
C. antisepsis.
D. sanitization.
E. ionization




Answer: C

The use of a physical or chemical process to destroy vegetative pathogens is

The use of a physical or chemical process to destroy vegetative pathogens is

A. disinfection.
B. sterilization.
C. antisepsis.
D. sanitization.
E. degermation.

Answer: A

The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is

The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is

A. disinfection.
B. sterilization.
C. antisepsis.
D. sanitization.
E. degermation.




Answer: D

The process that destroys or removes all microorganisms and microbial forms including bacterial endospores on inanimate objects is

The process that destroys or removes all microorganisms and microbial forms including bacterial endospores on inanimate objects is

A. disinfection.
B. sterilization.
C. antisepsis.
D. sanitization.
E. degermation.

Answer: B

Which of the following microbial forms have the highest resistance to physical and chemical controls?

Which of the following microbial forms have the highest resistance to physical and chemical controls?

A. naked viruses
B. protozoan cysts
C. fungal spores
D. bacterial endospores
E. yeast

Answer: D

_____ is a mechanism of release for enveloped viruses.

_____ is a mechanism of release for enveloped viruses.

A) Lytic replication
B) Persistent infection
C) Oncogenesis
D) Latency
E) Budding




Answer: E

Virus infection results in cancer in the process of

Virus infection results in cancer in the process of

A) lytic replication.
B) budding.
C) oncogenesis.
D) persistent infection.
E) latency.

Answer: C

Virus replication results in the death of the cell in a(n) __________ infection.

Virus replication results in the death of the cell in a(n) __________ infection.

A) lytic
B) latent
C) persistent
D) oncogenic
E) both latent and persistent

Answer: A

During __________, viruses remain dormant in a cell.

During __________, viruses remain dormant in a cell.

A) budding
B) latency
C) lytic replication
D) persistent infection
E) oncogenesis

Answer: B

Viruses are shed slowly and steadily during

Viruses are shed slowly and steadily during

A) lytic replication.
B) budding.
C) oncogenesis.
D) persistent infection.
E) latency.

Answer: D

Proteins are present in

Proteins are present in

A) cells only.
B) viruses only.
C) viroids only.
D) both cells and viruses.
E) cells, viruses, and viroids.

Answer: D

Cytoplasm is a characteristic of

Cytoplasm is a characteristic of

A) cells only.
B) viruses only.
C) both cells and viruses.
D) viroids only.
E) both viroids and viruses.

Answer: A

Double-stranded RNA genomes can be found

Double-stranded RNA genomes can be found

A) only in cells.
B) in both cells and viruses.
C) only in viruses.
D) in prions.
E) in both prions and viruses.

Answer: C

Double-stranded DNA genomes are found

Double-stranded DNA genomes are found

A) only in viroids.
B) only in cells.
C) only in viruses.
D) in both cells and viruses.
E) in both viruses and viroids.

Answer: D

A lipid membrane is present

A lipid membrane is present

A) only in viruses.
B) in both cells and viruses.
C) only in cells.
D) only in prions.
E) in both prions and viroids.

Answer: B

The infectious particles of fungi have RNA genomes and lack a capsid. They are therefore similar to

The infectious particles of fungi have RNA genomes and lack a capsid. They are therefore similar to

A) bacteriophages.
B) enveloped viruses.
C) prions.
D) viroids.
E) lysogens.




Answer: D

How are prions different from all other known infectious agents?

How are prions different from all other known infectious agents?

A) They cannot reproduce outside a cell.
B) They act as slow viruses.
C) They cause neurological problems.
D) They can be destroyed by incineration.
E) They lack nucleic acid.

Answer: E

Viroids infect

Viroids infect

A) bacteria.
B) plants.
C) fungi.
D) plants and animals.
E) all organisms.





Answer: B

Diploid cell cultures and continuous cell cultures differ in which of the following ways?

Diploid cell cultures and continuous cell cultures differ in which of the following ways?

A) longevity
B) source of cells
C) convenience of use
D) longevity and convenience of use
E) longevity and source of cells

Answer: E

Plaque assays are used for

Plaque assays are used for

A) evaluating the cancer-causing ability of a virus.
B) estimating the number of phages in a culture.
C) the study of prions.
D) cultivating viruses that cannot be grown any other way.
E) counting the number of latent phages in a cell.

Answer: B

Tumors invade other organs and tissues in a process called

Tumors invade other organs and tissues in a process called

A) neoplasia.
B) a plaque assay.
C) latency.
D) budding.
E) metastasis.




Answer: E

One mechanism by which viruses may cause cancer is to interrupt the genetic regulatory sequences of repressor proteins. Which of the following types of viruses is most likely to be involved in causing cancer by this mechanism?

One mechanism by which viruses may cause cancer is to interrupt the genetic regulatory sequences of repressor proteins. Which of the following types of viruses is most likely to be involved in causing cancer by this mechanism?

A) +ssRNA viruses
B) dsRNA viruses
C) -ssRNA viruses
D) retroviruses
E) +ssRNA and -ssRNA viruses

Answer: D

Which of the following individuals discovered prions?

Which of the following individuals discovered prions?

A) Lacks
B) Iwanowsky
C) Prusiner
D) Stanley
E) Rous




Answer: C

How is the HIV provirus different from a lambda phage prophage?

How is the HIV provirus different from a lambda phage prophage?

A) The HIV provirus is integrated permanently into the host cell's DNA.
B) All subsequent generations of HIV-infected cells carry the provirus.
C) All the offspring of a cell infected with a prophage will contain the virus.
D) The HIV provirus is inactive inside the host cell.
E) Lambda phage-infected cells produce virus slowly over time.

Answer: A

The majority of cases of infant diarrhea are caused by what kind of virus?

The majority of cases of infant diarrhea are caused by what kind of virus?

A) dsDNA viruses
B) dsRNA viruses
C) +ssRNA viruses
D) retroviruses
E) -ssRNA viruses




Answer: B

Which of the following membranes can give rise to a viral envelope?

Which of the following membranes can give rise to a viral envelope?

A) the nuclear membrane
B) the cytoplasmic membrane
C) the endoplasmic reticulum
D) the nuclear and cytoplasmic membranes
E) the nuclear and cytoplasmic membranes and the endoplasmic reticulum

Answer: E

In contrast to most dsDNA animal viruses, the poxviruses replicate solely in the cytoplasm of the host cell. This fact implies that the viral genome may encode

In contrast to most dsDNA animal viruses, the poxviruses replicate solely in the cytoplasm of the host cell. This fact implies that the viral genome may encode

A) reverse transcriptase.
B) a DNA polymerase.
C) RNA-dependent RNA transcriptase.
D) ribosome components.
E) reverse transcriptase and RNA-dependent RNA transcriptase.

Answer: B

Which of the following types of animal virus requires RNA-dependent RNA transcriptase to be replicated?

Which of the following types of animal virus requires RNA-dependent RNA transcriptase to be replicated?

A) +ssRNA viruses
B) ssDNA viruses
C) -ssRNA viruses
D) retroviruses
E) dsDNA viruses

Answer: C

The genome of which of the following types of animal virus can act directly as mRNA?

The genome of which of the following types of animal virus can act directly as mRNA?

A) retroviruses
B) +ssRNA viruses
C) -ssRNA viruses
D) ssDNA viruses
E) dsRNA viruses

Answer: B

Reverse transcriptase is associated with which of the following?

Reverse transcriptase is associated with which of the following?

A) dsDNA viruses
B) +ssRNA viruses
C) -ssRNA viruses
D) retroviruses
E) dsRNA viruses

Answer: D

Which of the following is matched INCORRECTLY?

Which of the following is matched INCORRECTLY?

A) poliovirus — direct penetration
B) herpesvirus — endocytosis
C) adenovirus — membrane fusion
D) measles virus — membrane fusion
E) HIV — membrane fusion

Answer: C

Zones of clearing in cell cultures that are the result of virus infection are called plaques. Sometimes "cloudy plaques" are seen on bacterial cultures infected with bacteriophage. What type of viral infection might cause this appearance?

Zones of clearing in cell cultures that are the result of virus infection are called plaques. Sometimes "cloudy plaques" are seen on bacterial cultures infected with bacteriophage. What type of viral infection might cause this appearance?

A) lytic
B) lysogenic
C) prion
D) viroid
E) transducing




Answer: B

Which of the following agents is capable of inducing conversion of a prophage back to a lytic phage?

Which of the following agents is capable of inducing conversion of a prophage back to a lytic phage?

A) UV light
B) X rays
C) presence of +ssRNA
D) UV light and X rays
E) UV light and +ssRNA

Answer: D

Why is lysogeny advantageous to a bacteriophage?

Why is lysogeny advantageous to a bacteriophage?

A) It speeds up the viral infection cycle.
B) The genetic material of the bacteriophage can be passed on to future generations of cells.
C) It allows the bacteriophage to infect cells it would not normally infect.
D) It allows the bacteriophage to destroy the host cell's DNA.
E) It enables the bacteriophage to take over the cell.

Answer: B

Which of the following events occurs in the lytic cycle of bacteriophage T4 infection but NOT in the lysogenic cycle?

Which of the following events occurs in the lytic cycle of bacteriophage T4 infection but NOT in the lysogenic cycle?

A) attachment
B) entry
C) digestion of host DNA
D) viral protein synthesis
E) both digestion of host DNA and viral proteins synthesis

Answer: C

The phenomenon of transduction is associated with which of the stages of a bacteriophage infection cycle?

The phenomenon of transduction is associated with which of the stages of a bacteriophage infection cycle?

A) attachment
B) assembly
C) release
D) synthesis
E) entry

Answer: B

The enzyme lysozyme is critical for which of the stages of a bacteriophage T4 infection cycle?

The enzyme lysozyme is critical for which of the stages of a bacteriophage T4 infection cycle?

A) entry
B) assembly
C) entry and release
D) synthesis
E) attachment




Answer: C

Which of the following is associated with the attachment of a bacteriophage to a bacterial cell?

Which of the following is associated with the attachment of a bacteriophage to a bacterial cell?

A) random collisions
B) chemical attractions
C) receptor specificity
D) chemical attractions and receptor specificity
E) random collisions, chemical attractions, and receptor specificity

Answer: E

Put the following stages of a lytic replication cycle in order, from earliest to latest stages:

Put the following stages of a lytic replication cycle in order, from earliest to latest stages:

I. Synthesis
II. Assembly
III. Attachment
IV. Release
V. Entry

A) III, V, I, II, IV
B) III, II, V, I, IV
C) V, III, II, IV, I
D) I, III, V, II, IV
E) I, II, III, V, IV

Answer: A

Which of the following statements comparing virus classification and taxonomy of organisms is true?

Which of the following statements comparing virus classification and taxonomy of organisms is true?

A) Both viruses and organisms are organized into classes.
B) The common names of viruses are their genus and species epithet, as they are with organisms.
C) Both viruses and organisms are organized into domains.
D) Genus and specific epithet are used in both classification systems.
E) Only families are common to both viral classification and organism taxonomy.

Answer: D

Which of the following statements regarding virus taxonomy is true?

Which of the following statements regarding virus taxonomy is true?

A) Viruses are classified on the basis of the taxonomy of their host organisms.
B) Virus classes are well established.
C) Some virus family names are derived from the name of an important member of the family.
D) The species epithet is a Latin descriptor of the virion structure.
E) Virus classes are based on the domain of the host organism.

Answer: C

Which of the following would NOT be found as a component of a bacteriophage?

Which of the following would NOT be found as a component of a bacteriophage?

A) envelope
B) icosahedral capsid
C) DNA
D) tail fibers
E) base plate

Answer: A

Which of the following infectious particles do NOT have protein in their structure?

Which of the following infectious particles do NOT have protein in their structure?

A) bacteriophages
B) prions
C) animal viruses
D) viroids
E) both prions and viroids

Answer: D

How are fungal viruses different from viruses that infect other organisms?

How are fungal viruses different from viruses that infect other organisms?

A) They have no extracellular state.
B) They have only DNA for genetic material.
C) They have no capsid.
D) They have no intracellular state.
E) They cannot pass through a filter.

Answer: A

Who was the first person to demonstrate the existence of viruses?

Who was the first person to demonstrate the existence of viruses?

A) Stanley
B) Rous
C) Lacks
D) Ivanowsky
E) Prusiner




Answer: D

Host specificity of a virus is due to

Host specificity of a virus is due to

A) particular genes that it shares with the infected cell.
B) the presence of an envelope.
C) differences in size between the virus and the host cell.
D) the presence or absence of a cell wall on the host cell.
E) interactions between viral and cellular surface molecules.

Answer: E

Viruses are primarily classified according to their

Viruses are primarily classified according to their

A) type of nucleic acid.
B) type of life cycle.
C) number of chromosomes.
D) shape.
E) size.

Answer: A

During the intracellular state, a virus exists as

During the intracellular state, a virus exists as

A) a lipid.
B) a protein.
C) a nucleic acid.
D) both a protein and a nucleic acid.
E) both a lipid and a nucleic acid.

Answer: C

The outermost layer of a virion fulfills which of the following functions of the virus?

The outermost layer of a virion fulfills which of the following functions of the virus?

A) protection
B) recognition
C) replication
D) protection and recognition
E) recognition and replication





Answer: D

Which of the following statements concerning viruses is FALSE?

Which of the following statements concerning viruses is FALSE?

A) Viruses never contain both DNA and RNA.
B) Viruses enter a cell to complete the replication they have begun extracellularly.
C) Some viruses have an outer membrane called an envelope.
D) Viral capsids can assume one of three basic shapes.
E) Tobacco mosaic virus was the first virus to be discovered and characterized

Answer: B